RV glossary: 178 RV terms and acronyms explained

Plain-English definitions of RV terms, from GVWR, UVW and CCC to dogbone adapters, black tanks and boondocking. Search, or browse by letter or category.

New to RV weights? Read RV weight terms explained (GVWR, UVW, CCC, payload, GCWR and tongue weight with a real example).

#

7-pin connector 7-way plug: The round seven-terminal plug that connects a trailer to the tow vehicle for running lights, turn signals, brake lights, electric brakes, reverse lights and a 12-volt charge line.Hitches & towing gear
12-volt compressor fridge 12V fridge: A refrigerator that runs directly on the RV’s 12-volt battery system with an efficient compressor. Increasingly common in new RVs; battery capacity and solar matter when boondocking.Floorplans & features
30-amp service 30 amp: A single 120-volt, 30-amp electrical connection, used by most travel trailers and smaller RVs. It provides up to about 3,600 watts, enough for one A/C plus a few other appliances. More about 30-amp service →Electrical & power
50-amp service 50 amp: A 120/240-volt service with two 50-amp legs, used by larger RVs with two or three air conditioners. It can supply up to about 12,000 watts, far more than 30-amp. More about 50-amp service →Electrical & power
80% rule 80 percent rule: A common rule of thumb: keep a trailer’s loaded weight (or GVWR) at or below 80% of your vehicle’s tow rating. It leaves a margin for wind, hills, heat and rating optimism. It’s a guideline, not a legal limit. More about 80% rule →Weights & towing limits

A

A-frame camper: A small folding trailer with hard panels that raise into a triangular A-shape at camp. Quick to set up and light to tow.RV types
Absorption refrigerator Gas/electric fridge · 2-way fridge: The traditional RV refrigerator, which can run on propane or 120-volt power. It works silently but cools more slowly and needs the RV to be fairly level.Floorplans & features
AGM battery: A sealed, maintenance-free lead-acid battery (absorbed glass mat). Better than flooded batteries but heavier than lithium, and should not be regularly discharged below about half.Electrical & power
Amp-hours Ah: A measure of battery capacity: how many amps a battery can supply for how many hours. A 100 Ah battery can, in theory, supply 5 amps for 20 hours.Electrical & power
Anode rod: A sacrificial metal rod in steel-tank RV water heaters that corrodes instead of the tank. Check and replace it periodically; aluminum tanks usually don’t use one.Water & holding tanks
ASME tank: A permanently mounted propane tank, common on motorhomes, filled in place instead of removed for refills.Propane & appliances
Awning Power awning: A retractable fabric shade on the side of an RV. Most new RVs have powered awnings, some with LED lights and wind sensors. Retract it in strong wind.Floorplans & features

B

Back-in site: A campsite you reverse into. More common than pull-throughs; check the site length against your RV and tow vehicle.Camping & travel
Ball mount Drawbar: The removable bar that slides into the receiver and holds the hitch ball. Its drop or rise is chosen so the trailer rides level.Hitches & towing gear
Bath and a half 1.5 bath: A floorplan with a full bathroom plus a second half bath (toilet and sink), common in large family fifth wheels and travel trailers.Floorplans & features
Battery disconnect: A switch that cuts power from the house batteries to prevent small loads from draining them during storage.Electrical & power
Big rig: A large RV, usually 35 feet or longer. “Big rig friendly” campgrounds have long, wide sites and roads that can handle them.Camping & travel
Black tank Black water tank: The holding tank connected to the toilet. It is emptied at a dump station or sewer hookup, typically before the gray tank. More about Black tank →Water & holding tanks
Black tank flush: A built-in connection that sprays water inside the black tank to rinse it after dumping. Use a dedicated hose, never your drinking water hose.Water & holding tanks
BLM land Bureau of Land Management: Public land managed by the federal Bureau of Land Management, mostly in the western U.S., much of which allows dispersed camping.Camping & travel
Boondocking Dry camping · Off-grid camping: Camping without hookups (no water, sewer or electric), often on public land. How long you can stay depends on your tanks, batteries and propane. More about Boondocking →Camping & travel
Brake controller: A device in the tow vehicle that applies the trailer’s electric brakes in proportion to the vehicle’s braking. Most travel trailers and fifth wheels require one; many trucks have one built in.Hitches & towing gear
Breakaway switch: A safety device with a cable attached to the tow vehicle. If the trailer separates, the cable pulls a pin that applies the trailer brakes using the trailer’s battery.Hitches & towing gear
Bunkhouse Bunk model: An RV floorplan with bunk beds, often in a separate area or second bedroom. Popular with families; bunkhouse model names often include “BH.”RV types

C

Carbon monoxide detector CO detector: An alarm that warns of carbon monoxide from generators, propane appliances or nearby vehicles. Required in RVs; replace it as directed by the manufacturer.Propane & appliances
Cassette toilet: A toilet with a small removable waste tank, emptied by carrying it to a toilet or dump station. Common in camper vans and compact RVs without a black tank.Water & holding tanks
CAT scale Truck scale: A certified truck scale, commonly found at truck stops, where you can weigh your loaded rig axle by axle. Weighing is the only way to know your real tongue weight, axle weights and total weight.Weights & towing limits
CCC Cargo Carrying Capacity: How much weight you can add to a towable RV: GVWR minus UVW. Everything you load counts against it, including water in the tanks, propane, food, gear, batteries and dealer-installed options. More about CCC →Weights & towing limits
Charge controller MPPT · PWM: A device between solar panels and batteries that regulates charging. MPPT controllers are more efficient than simpler PWM controllers.Electrical & power
Chassis Frame: The structural base of an RV: the steel frame of a trailer, or the truck or van platform of a motorhome, including engine, axles and suspension.Construction & chassis
City water connection: An inlet that connects the RV directly to a pressurized campground water spigot, bypassing the fresh tank and water pump. Use a pressure regulator.Water & holding tanks
Class A motorhome Class A: The largest motorhomes, built on a bus-style or commercial truck chassis with a flat front and a large windshield. They can be gas (front engine) or diesel (usually a rear-engine diesel pusher). More about Class A motorhome →RV types
Class B motorhome Camper van · Class B: A camper van: a motorhome built inside a full-size van such as a Mercedes Sprinter, Ford Transit or Ram ProMaster. The smallest motorhomes, easy to drive and park. More about Class B motorhome →RV types
Class B+ B+ motorhome: A small motorhome between a Class B and a Class C, usually built on a cutaway van chassis with a low-profile cab instead of a full over-cab bunk. Manufacturers use the term differently.RV types
Class C motorhome Class C: A motorhome built on a cutaway van or truck chassis with the original cab, usually recognizable by the over-cab bunk or storage area. Typically 21 to 33 feet. More about Class C motorhome →RV types
Composting toilet: A waterless toilet that separates liquids and mixes solids with a material like coconut coir. Popular with boondockers because it needs no black tank.Water & holding tanks
Converter Converter/charger: Changes 120-volt AC power from shore power or a generator into 12-volt DC to run lights, pumps and fans and charge the house batteries. More about Converter →Electrical & power
Coupler: The part at the front of a trailer’s tongue that latches over the hitch ball. Coupler size (often 2 in. or 2-5/16 in.) must match the ball.Hitches & towing gear
Curb weight: What a vehicle weighs with standard equipment and full fluids but no passengers or cargo. GVWR minus curb weight equals payload.Weights & towing limits

D

Dealer prep fee Prep fee · Freight & prep: A fee some dealers charge for getting a new RV ready for delivery: inspection, cleaning, setup and sometimes freight. Amounts vary widely; ask for the out-the-door price.Buying & owning
Delamination: When the outer fiberglass skin separates from the wall structure, usually from water intrusion, causing bubbles or waves. It’s expensive to repair, so inspect walls when buying.Construction & chassis
Depreciation: The loss of an RV’s value over time. New RVs often lose a large share of their value in the first few years, which is why some buyers choose lightly used models.Buying & owning
Destination trailer: A large travel trailer designed to stay in one place for long periods, such as a seasonal campsite, with residential-style features. It can be towed but isn’t meant for frequent travel.RV types
Dewinterizing: Getting the plumbing ready for use after storage: flushing out antifreeze, closing drains, refilling and sanitizing the fresh water system and checking for leaks.Water & holding tanks
Diesel pusher DP: A Class A motorhome with a diesel engine at the rear, which keeps the cab quieter and typically gives more torque, towing capacity and air-ride suspension.RV types
Dinette Booth dinette: The RV’s eating area: a table with bench seats or chairs. Many dinettes convert to a bed, which manufacturers include in sleeping capacity.Floorplans & features
Dispersed camping: Free camping outside developed campgrounds on public land such as national forests and BLM land, usually with stay limits (often 14 days) and no facilities.Camping & travel
Dogbone adapter Power adapter: A short adapter cord for plugging an RV into a different pedestal outlet, such as a 30-amp RV into a 50-amp outlet or a 50-amp RV into a 30-amp outlet. The RV is limited by the smaller of the two. More about Dogbone adapter →Electrical & power
Dry camping: Camping in an RV without hookups. Often used interchangeably with boondocking, though dry camping can also mean a campground site with no hookups.Camping & travel
Dry weight Unloaded weight: A common name for an RV’s unloaded vehicle weight (UVW): its weight empty, without water or your gear. What it includes, such as propane or batteries, varies by manufacturer.Weights & towing limits
Dually DRW · Dual rear wheels: A pickup with two tires on each side of the rear axle. The extra tires increase payload and stability, which is why duallies are popular for heavy fifth wheels. SRW means single rear wheels.Weights & towing limits
Ducted A/C: An air conditioner that sends cool air through ducts in the ceiling to vents around the RV, giving quieter and more even cooling than a single non-ducted unit.Floorplans & features
Dump station Sani-dump: A place to empty an RV’s gray and black tanks through a sewer hose into an underground drain. Found at campgrounds, truck stops, rest areas and some fuel stations, sometimes for a fee. More about Dump station →Water & holding tanks

E

Electric brakes: The standard brakes on most RV trailers: electromagnets in each drum (or an electric-over-hydraulic system for discs) activated by the tow vehicle’s brake controller.Hitches & towing gear
Enclosed underbelly: A sealed bottom panel that covers the tanks and plumbing, protecting them from road debris and helping keep them from freezing.Construction & chassis
Extended warranty Service contract: An optional service contract covering repairs after the manufacturer’s warranty ends. Coverage, deductibles and exclusions vary widely; read the contract before buying.Buying & owning

F

Fiberglass walls Gelcoat fiberglass: Smooth, glossy exterior walls made of fiberglass panels. They look clean and resist dents but can delaminate if water gets into the wall.Construction & chassis
Fifth wheel 5th wheel · Fiver: A towable RV with a raised front section that extends over the bed of a pickup and connects to a fifth-wheel hitch. The hitch position gives very stable towing, and the raised front usually holds the bedroom. More about Fifth wheel →RV types
Fifth-wheel hitch: A heavy-duty hitch mounted in a pickup bed, over or slightly ahead of the rear axle, that locks onto a fifth wheel’s kingpin. It places the pin weight where the truck can carry it best, giving stable towing.Hitches & towing gear
Flat towing Four-down towing · Dinghy towing: Towing a car behind a motorhome with all four wheels on the road, using a tow bar and base plate. The car’s manufacturer must approve it, and a supplemental braking system is usually required.Hitches & towing gear
Floorplan Floor plan: The layout of an RV’s interior, shown as a drawing from above. Model numbers usually encode the length and layout, such as 26RL for a roughly 26-foot rear living model, though conventions vary by manufacturer.Floorplans & features
Four-season package Arctic package · Polar package: Extra insulation, enclosed and heated underbellies and tank heaters for cold-weather camping. Package names and real cold-weather performance vary by manufacturer.Construction & chassis
Fresh water tank Fresh tank: The tank holding clean water for drinking, cooking, washing and flushing when you’re not connected to a water hookup. Water weighs about 8.3 lb per gallon, so a full tank adds significant weight.Water & holding tanks
Front bedroom: The most common RV layout, with the main bedroom at the front. In fifth wheels it sits in the raised section over the truck bed.Floorplans & features
Front kitchen FK: A floorplan with the kitchen at the front of the RV, often with a wraparound counter and large windows. Model names often include “FK.”Floorplans & features
Full hookups FHU: A campsite with water, sewer and electric connections. More about Full hookups →Camping & travel
Full-timer Full-time RVer: Someone who lives in their RV year-round instead of a fixed home.Camping & travel
Furnace: The RV’s main heater, usually propane-fired with a 12-volt blower. The blower draws significant battery power when boondocking in cold weather.Propane & appliances

G

Gasser: Slang for a gas-powered motorhome, usually a front-engine Class A or a Class C.RV types
GAWR Gross Axle Weight Rating: The most weight a single axle (front or rear) is rated to carry. On a tow vehicle, the trailer’s tongue or pin weight pushes down on the rear axle, so a heavy trailer can exceed the rear GAWR before anything else.Weights & towing limits
GCWR Gross Combined Weight Rating: The maximum allowed weight of a tow vehicle and its trailer together, both fully loaded. It’s set by the vehicle manufacturer and is often the hidden limit when towing heavy trailers. More about GCWR →Weights & towing limits
Generator Onboard generator · Inverter generator: A gas, diesel or propane engine that produces 120-volt power away from hookups. Motorhomes often have one built in; trailer owners often carry quiet portable inverter generators.Electrical & power
Generator prep: Wiring, a compartment or a fuel connection prepared for adding a generator later. The generator itself is usually not included.Electrical & power
Gooseneck hitch: A ball mounted in the truck bed for gooseneck trailers. Some fifth wheels can use a gooseneck hitch with a kingpin adapter; check the trailer manufacturer’s rules, as some void warranties.Hitches & towing gear
Gray tank Grey water tank: The holding tank for used water from the sinks and shower. Many RVs have more than one gray tank. More about Gray tank →Water & holding tanks
GVW Gross Vehicle Weight: What a vehicle or RV actually weighs at a given moment, loaded as it is. Unlike GVWR (a limit), GVW is measured, usually at a truck scale.Weights & towing limits
GVWR Gross Vehicle Weight Rating: The maximum an RV (or a truck) is allowed to weigh when fully loaded, including everything inside it: cargo, water, propane, batteries and, for motorhomes, passengers. It is set by the manufacturer and printed on the weight label. More about GVWR →Weights & towing limits

H

Half-ton truck 1/2-ton · 150/1500 series: A full-size light-duty pickup such as an F-150, Silverado 1500, Ram 1500 or Tundra. The name is historical; payloads today are typically 1,300–2,300 lb, which is often the limiting factor for towing.Weights & towing limits
Heat pump: A rooftop A/C unit that can also run in reverse to heat the RV with electricity, saving propane in mild weather. It becomes less effective near freezing, when the furnace takes over.Floorplans & features
Hitch class Class I–V hitch: A rating for receiver hitches. Class I and II are for light loads; Class III (2-inch receiver) is common for travel trailers; Class IV and V handle heavier trailers. The vehicle’s own tow rating still applies, whichever is lower.Hitches & towing gear
Hitch weight Tongue weight: The downward force a bumper-pull trailer puts on the tow vehicle’s hitch, typically 10–15% of the trailer’s loaded weight. Too little tongue weight can cause sway; too much can overload the truck’s rear axle and payload. More about Hitch weight →Weights & towing limits
Holding tanks: A general term for an RV’s fresh, gray and black water tanks.Water & holding tanks
House batteries Coach batteries: The 12-volt batteries that power the RV’s living area (lights, water pump, fans, slide motors and furnace fan), separate from a motorhome’s chassis battery.Electrical & power
Hybrid camper Expandable trailer: A hard-sided travel trailer with fold-out tent beds at one or both ends, combining a light towing weight with extra sleeping space.RV types

I

Induction cooktop: An electric cooktop that heats compatible pans with magnetic fields. Increasingly common in RVs, sometimes alongside propane burners; it needs shore power, a generator or a large battery and inverter.Propane & appliances
Inverter: Changes 12-volt battery power into 120-volt AC so you can use outlets and appliances without shore power. Pure sine wave inverters are best for electronics. More about Inverter →Electrical & power
Island kitchen Kitchen island · Mid kitchen · MK: A kitchen with a freestanding island, usually mid-coach in larger fifth wheels and travel trailers. A “middle kitchen” (MK) floorplan places the kitchen in the center.Floorplans & features

J

Jackknife sofa: A sofa whose back folds flat to make a bed, common in RVs.Floorplans & features

K

Kingpin Pin box: The downward-facing pin at the front of a fifth wheel that locks into the fifth-wheel hitch. The surrounding structure is called the pin box.Hitches & towing gear

L

Laminated walls Vacuum-bonded walls: Walls built as a sandwich of exterior fiberglass, insulation foam and an interior panel bonded together, often with an aluminum frame. Stiffer and smoother than stick and tin.Construction & chassis
Leaf spring suspension: The traditional trailer suspension, using stacked steel springs connected by equalizers between axles. Simple and inexpensive.Construction & chassis
Leveling blocks: Stackable plastic blocks or ramps you drive onto to level an RV side to side on an uneven site.Camping & travel
Leveling system Auto-leveling: Hydraulic or electric jacks that lift and level an RV, often automatically at the push of a button. Common on fifth wheels and motorhomes; many travel trailers level with blocks and the tongue jack instead.Hitches & towing gear
Lithium battery LiFePO4: Lithium iron phosphate (LiFePO4) RV batteries are lighter than lead-acid, can use most of their capacity and last many more charge cycles. They cost more and need compatible charging.Electrical & power
Load range: A letter rating (such as C, D or E) for how much weight a tire can carry at its maximum inflation pressure. Higher load ranges carry more weight.Construction & chassis
Loft: A raised sleeping area above another room, common in destination trailers and some toy haulers and fifth wheels.Floorplans & features
Low-point drains: Valves at the lowest points of the fresh water lines that let you drain them, usually when winterizing.Water & holding tanks

M

Macerator: A pump that grinds waste and pushes it through a narrow hose, so tanks can be emptied into a toilet or cleanout that is uphill or far away.Water & holding tanks
Manufacturer warranty: The RV builder’s warranty, often one year for the whole RV and longer for the structure. Appliances, chassis and components often carry their own separate warranties.Buying & owning
Model year MY: The year a manufacturer assigns to an RV model, which often starts months before the calendar year. Floorplans, features and specs can change between model years.Buying & owning
Moochdocking: Camping in a friend’s or relative’s driveway or property, sometimes with a power cord or water hose.Camping & travel
MSRP Manufacturer’s Suggested Retail Price: The price the manufacturer suggests for an RV. Dealers commonly sell RVs well below MSRP, so it’s best used as a reference point rather than the expected price. More about MSRP →Buying & owning
Murphy bed: A bed that folds up into a wall or sofa when not in use, freeing floor space in small RVs.Floorplans & features

O

OCCC Occupant and Cargo Carrying Capacity: The motorhome version of cargo capacity: how much weight the people riding in it plus all cargo, water and gear can add before the motorhome reaches its GVWR.Weights & towing limits
One-ton truck 350/3500 series: The heaviest common consumer pickups, such as an F-350, Silverado 3500 or Ram 3500, available with single or dual rear wheels. Used for the heaviest fifth wheels and toy haulers.Weights & towing limits
Outdoor kitchen Outside kitchen: A kitchen compartment on the outside of the RV, with features such as a griddle or burner, mini fridge and sink. Contents vary widely by model and some are optional.Floorplans & features
Overlanding: Self-reliant travel to remote places, usually off-road, with a rugged vehicle or off-road trailer.Camping & travel

P

Park model RV PMRV: A small home-like unit built on a trailer chassis, typically up to about 400 square feet, intended for long-term placement at a campground or RV resort rather than travel.RV types
Partial hookups W/E: A campsite with some connections, usually water and electric but no sewer. You dump tanks at a dump station.Camping & travel
Pass-through storage Basement storage: A storage compartment under the floor that runs the width of the RV, accessible from both sides. Fifth wheels and motorhomes often have large basements.Floorplans & features
Payload capacity Payload: How much weight a truck or SUV can carry: its GVWR minus its curb weight. Passengers, cargo, the hitch itself and the trailer’s tongue or pin weight all count against payload. More about Payload capacity →Weights & towing limits
PDI Pre-delivery inspection: A thorough inspection of an RV before you take delivery, checking every system. Many buyers do their own PDI or hire an inspector before signing. More about PDI →Buying & owning
Pin weight Kingpin weight: The weight a fifth wheel puts on the hitch in the truck bed, usually about 15–25% of the trailer’s loaded weight. It is the fifth-wheel equivalent of tongue weight and often decides whether a truck has enough payload.Weights & towing limits
Pop-up camper Tent trailer · Folding camper: A lightweight trailer whose canvas sides and beds fold out at camp and collapse into a low box for towing. Easy to tow and store, but less insulated than hard-sided RVs.RV types
Propane LP · LPG: The gas most RVs use for the furnace, water heater, stove and (in some) the refrigerator. Trailers usually carry two 20- or 30-lb cylinders; motorhomes have a built-in ASME tank.Propane & appliances
Propane detector LP detector: An alarm near the floor that warns of propane leaks. Propane is heavier than air, so detectors are mounted low. Test it regularly.Propane & appliances
Pull-through site: A campsite you can drive into and out of without backing up, popular with long rigs and anyone towing.Camping & travel

Q

Quiet hours Generator hours: Campground rules limiting noise, and often generator use, during set hours (commonly 10 p.m. to 7 or 8 a.m.).Camping & travel

R

Ramp door Rear ramp: The large rear door on a toy hauler that folds down into a loading ramp. Many can be set up as a patio deck with railings.Floorplans & features
Rear bath RB: A floorplan with the bathroom across the back of the RV, often with a larger shower and more privacy from the living area.Floorplans & features
Rear kitchen RK: A floorplan with the kitchen across the back of the RV, common in fifth wheels and travel trailers. Model names often include “RK.”Floorplans & features
Rear living RL: A floorplan with the living room at the back of the RV, often with a large rear window, recliners or theater seating. Model names often include “RL.”Floorplans & features
Receiver hitch: The square tube mounted under a vehicle’s rear bumper that accepts a ball mount or weight-distribution hitch. Receivers are rated by class (I to V) with maximum trailer and tongue weights.Hitches & towing gear
Residential refrigerator: A household-style electric refrigerator instead of an RV propane/electric fridge. It needs shore power, a generator or a strong battery and inverter system when not plugged in.Floorplans & features
Rig: Slang for an RV, or for a whole setup such as a truck and the trailer it tows.RV types
Roof sealant Self-leveling sealant: Caulk-like sealant around roof vents, edges and fixtures that keeps water out. Inspecting it at least once or twice a year is one of the most important RV maintenance jobs.Buying & owning
RVIA seal: A seal from the RV Industry Association showing the RV was built to industry safety standards for electrical, plumbing, propane and fire safety. Some campgrounds and lenders require it.Buying & owning

S

Safety chains: Chains connecting a bumper-pull trailer to the tow vehicle as a backup if the coupler fails. They’re usually crossed under the tongue so they can cradle it.Hitches & towing gear
Sewer hose: A flexible hose connecting the RV’s tank outlet to a dump station or sewer hookup. Wear gloves and keep it separate from fresh water hoses.Water & holding tanks
Ship weight Shipping weight: The weight of an RV as it leaves the factory, as listed by some manufacturers (especially for motorhomes). Like dry weight, it doesn’t include your cargo or water.Weights & towing limits
Shore power: Plugging the RV into an electrical pedestal at a campground or home to run 120-volt appliances and charge the batteries.Electrical & power
Sleeping capacity Sleeps: The number of people a manufacturer says an RV can sleep, counting convertible dinettes and sofas as beds. Real comfortable capacity is often lower.Floorplans & features
Slide topper Slide awning: A small fabric awning over a slide-out that keeps leaves and water off the slide roof.Floorplans & features
Slide-out Slide · Slideout: A section of the RV wall that extends outward at camp to add floor space, driven by electric or hydraulic mechanisms. Slides add weight and moving parts but make interiors much roomier. More about Slide-out →Floorplans & features
Slider hitch Short-bed hitch: A fifth-wheel hitch that slides rearward for tight turns, used with short-bed (about 6.5 ft or shorter) pickups so the trailer’s front cap doesn’t hit the cab. Some fifth wheels instead have a cap shape or pin box designed for short beds.Hitches & towing gear
Snowbird: Someone who travels to a warm region for the winter, often staying at an RV resort for months.Camping & travel
Solar panels RV solar: Panels that charge the house batteries from sunlight, extending time off-grid. How much they help depends on panel wattage, battery capacity, sun and your power use.Electrical & power
Solar prep: A roof or side port wired to the battery area, so solar panels can be added later. Usually no panels or charge controller are included.Electrical & power
ST tires Special Trailer tires: Tires designed for trailers, with stiffer sidewalls for the loads and sway forces trailers create. They age out before they wear out; many owners replace them every 5–6 years.Construction & chassis
Stabilizer jacks: Jacks at the corners of a trailer that reduce bouncing and rocking when parked. They are not designed to lift or level the RV.Hitches & towing gear
Stick and tin Stick-built: A traditional RV wall built from a wood frame with corrugated aluminum siding. It’s lighter and cheaper to repair but more prone to water damage if seals fail.Construction & chassis
Super C motorhome Super C: A large Class C built on a heavy-duty truck chassis, often a diesel medium-duty truck. Super Cs offer high towing capacity and a conventional truck cab.RV types
Surge protector EMS · Electrical management system: A device between the pedestal and the RV that protects against power surges. An EMS also shuts off power for dangerous problems like high or low voltage, reversed polarity or open grounds. More about Surge protector →Electrical & power
Sway Trailer sway: Side-to-side movement of a trailer behind the tow vehicle, often triggered by wind, passing trucks or too little tongue weight. Sway control devices and correct loading reduce it; if it starts, ease off the accelerator and apply the trailer brakes gently using the brake controller. More about Sway →Weights & towing limits
Sway control Anti-sway bar: A device, usually part of or added to a weight-distribution hitch, that resists the trailer pivoting side to side. Types include friction bars, cam systems and integrated designs.Hitches & towing gear

T

Tank heaters Holding tank heaters: Electric heating pads attached to the holding tanks to keep them from freezing in cold weather. They run on 12-volt or 120-volt power, so they use battery power when you’re not plugged in.Construction & chassis
Tankless water heater On-demand water heater: A water heater that heats water as it flows, usually with propane, instead of keeping a tank hot. Many RVs still use 6- to 10-gallon tank water heaters with propane and electric elements.Water & holding tanks
Teardrop trailer: A very small, aerodynamic trailer with a sleeping area inside and, often, a galley kitchen under a rear hatch. Many weigh under 2,000 lb and can be towed by cars.RV types
Theater seating: Recliner chairs, often powered and with cup holders, used instead of a sofa in many rear living and larger RVs.Floorplans & features
Three-quarter-ton truck 3/4-ton · 250/2500 series: A heavy-duty pickup such as an F-250, Silverado 2500 or Ram 2500, with stronger frames, springs and brakes and much higher payload than a half-ton. A common choice for larger travel trailers and many fifth wheels.Weights & towing limits
Tire date code DOT code: The last four digits of a tire’s DOT code, showing the week and year it was made (for example 2324 means week 23 of 2024). Useful for knowing how old RV tires really are.Construction & chassis
Toad Towed car · Dinghy: A car towed behind a motorhome, so you can leave the motorhome parked at camp. Only some vehicles can be flat-towed; others need a tow dolly or trailer. More about Toad →Hitches & towing gear
Tongue jack: The jack on the trailer tongue used to raise and lower it onto the hitch ball and to level the trailer front to back. Power tongue jacks are common.Hitches & towing gear
Torsion axle: An axle that uses rubber cords inside a tube for suspension instead of leaf springs, giving independent wheel movement and a smoother ride.Construction & chassis
Tow dolly: A small two-wheel trailer that lifts a car’s front wheels so it can be towed behind a motorhome with its rear wheels rolling.Hitches & towing gear
Tow mirrors Extended mirrors: Mirrors that extend outward so the driver can see past a wide trailer. Many states require a view down both sides of the trailer.Hitches & towing gear
Tow rating Towing capacity · Max trailer weight: The maximum trailer weight a vehicle is rated to pull, as published by its manufacturer. It depends on engine, axle ratio, cab, bed, drivetrain and tow package, so the same model can have very different ratings. More about Tow rating →Weights & towing limits
Toy hauler Sport utility RV: An RV with a rear garage and ramp door for carrying motorcycles, ATVs, side-by-sides or bikes. The garage often doubles as living space with fold-down beds or sofas, and the ramp can become a patio. More about Toy hauler →RV types
TPO roof EPDM roof · Rubber roof: A membrane roof made of TPO or EPDM rubber over a wood deck, used on most travel trailers and fifth wheels. Seals around vents and edges need regular inspection.Construction & chassis
Travel trailer Bumper pull · TT: A towable RV that attaches to a hitch on the tow vehicle’s rear bumper or receiver. Travel trailers range from small single-axle models to 40-foot-plus family trailers. More about Travel trailer →RV types
Truck camper Slide-in camper: A camper that sits in a pickup bed. It needs a truck with enough payload for the camper’s wet weight plus passengers, which often means a heavy-duty truck.RV types

U

U-shaped dinette U-dinette: A dining area with seating on three sides of the table. It usually converts into a bed.Floorplans & features
Ultra-lite trailer Lightweight trailer: A marketing term for travel trailers built to be light enough for SUVs and half-ton trucks. There’s no standard definition, so compare the actual GVWR rather than the label.RV types
UVW Unloaded Vehicle Weight · Dry weight: What the RV weighs as it leaves the factory, without cargo, water or (usually) propane. Manufacturers often list it as UVW or “dry weight.” More about UVW →Weights & towing limits

W

Walk-through: The dealer’s orientation at delivery, showing you how to use the RV’s systems: hitching, slides, water, electrical, propane and appliances.Buying & owning
Walkable roof: A roof built to support a person’s weight for cleaning and maintenance. Not every RV roof is walkable; check the manufacturer’s guidance before climbing up.Construction & chassis
Washer/dryer prep: Plumbing, power and space set aside for a washer and dryer, usually in a closet. The appliances themselves are usually sold separately.Floorplans & features
Water heater bypass Bypass valve: Valves that route water around the water heater, so you don’t fill it with antifreeze when winterizing.Water & holding tanks
Water pressure regulator: A fitting that limits incoming campground water pressure (often to about 40–50 psi) to protect the RV’s plumbing.Water & holding tanks
Water pump: A 12-volt pump that pressurizes water from the fresh tank when you aren’t connected to city water.Water & holding tanks
Weight distribution: How a trailer’s weight is spread between its axles and the tow vehicle. Good distribution (proper tongue weight, heavy items low and over the axles) reduces sway and keeps steering and braking predictable.Weights & towing limits
Weight-distribution hitch WDH · WD hitch: A hitch with spring bars that shift some of a trailer’s tongue weight forward to the tow vehicle’s front axle and back to the trailer axles. It levels the rig and restores steering and braking. Many vehicles require one above a certain trailer weight. More about Weight-distribution hitch →Hitches & towing gear
Wet weight: An informal term for an RV’s weight with its tanks full and propane loaded, as opposed to dry weight. It’s not a standard rating, so numbers quoted as “wet weight” vary.Weights & towing limits
Wheel bearing repack: Cleaning and re-greasing a trailer’s wheel bearings and inspecting the brakes, usually every year or every 10,000–12,000 miles depending on the axle maker.Buying & owning
Wheel chocks Chocks: Wedges placed against a trailer’s tires so it can’t roll when unhitched. Always chock before uncoupling.Hitches & towing gear
Wide-body: An RV built at or near the maximum common width of 8 feet 6 inches instead of a narrower body, for more interior room. Wide bodies may exceed some park road width limits.Floorplans & features
Winterizing: Preparing an RV’s plumbing for freezing temperatures by draining the tanks, lines and water heater and either blowing the lines out with air or filling them with RV antifreeze. More about Winterizing →Water & holding tanks
Workamping Workamper: Working seasonal jobs, often at campgrounds or parks, in exchange for a free site and sometimes pay, while living in an RV.Camping & travel

Tools that use these terms

What can my vehicle tow? · Payload calculator · Boondocking calculator · Floorplan finder · National park RV rules