RV Glossary of Terms


  • 120 AC/12 DC/LP-gas – The power sources on which RV refrigerators operate; 120 AC is 120-volt alternating current (same as in houses); 12 DC is 12-volt direct current (same as in motor vehicles); LP-gas. Some RV refrigerators can operate on two of the three sources, others on all three.
  • Auxiliary battery – Extra battery to run 12-volt equipment.
  • Back-up monitor – Video camera mounted on rear of motorhome to assist the driver visually with backing up the motorhome, via a monitor mounted in the driver’s compartment or in a central area of the cab where it can be viewed by the driver from the driver’s seat. Also, these monitors are usually left in the ‘on’ position to assist the driver with the flow of traffic behind the motorhome and in watching a “towed” vehicle.
  • Ball Mount – The part of the hitch system that supports the hitch ball and connects it to the trailer coupler. Ball mounts are available in load-carrying and weight-distributing configurations.
  • Black Water – Waste (sewage) from the toilet that is flushed into a black water holding tank, usually located beneath the main floor of the RV.
  • Brake Controller – A control unit mounted inside the vehicle that allows electric trailer brakes to become activated in harmony with the braking of the tow vehicle. This device can be used to adjust trailer brake intensity, or to manually activate the trailer brakes.
  • Breakaway Switch – A safety device that activates the trailer brakes in the event the trailer becomes accidentally disconnected from the hitch while traveling.
  • Bumper-Pull – Slang term regarding the hitch or towing method for a conventional travel trailer or popup; receiver and ball-mount type hitch.
  • Bunkhouse – An RV area containing bunk beds instead of regular beds.


  • Cabcover – The part of a type C mini-motorhome that overlaps the top of the vehicle’s cab, usually containing a sleeping or storage unit.
  • Chassis Battery – Battery in motorhome for operating 12 volt components of drivetrain.
  • Class A Motorhome – An RV with the living accommodations built on or as an integral part of a self-propelled motor vehicle. Models range from 24 to 40 feet long.
  • Class B Motorhome – Also known as a camping van conversion. These RVs are built within the dimensions of a van, but with a raised roof to provide additional headroom. Basic living accommodations inside are ideal for short vacations or weekend trips. Models usually range from 16 to 21 feet.
  • Class C Motorhome – An RV with the living accommodations built on a cutaway van chassis. A full-size bed in the cabover section allows for ample seating, galley and bathroom facilities in the coach. Also called a “mini-motorhome” or “mini.” Lengths range from approximately 16 to 32 feet.
  • Coach – Another name for a motorhome
  • Converter – An electrical device for converting 120-volt AC power into 12-volt DC power. Most RVs with electrical hookups will have a converter, since many of the lights and some other accessories run on 12-vold DC.
  • Coupler – The part of a trailer A-frame that attaches to the hitch ball.
  • Curb Weight – The weight of a basic RV unit without fresh or waste water in the holding tanks but with automotive fluids such as fuel, oil, and radiator coolant.

D - E

  • Dinette – booth-like dining area. Table usually drops to convert unit into a bed at night.
  • Dry Camping – Camping in an RV without benefit of electricity, fresh water, and sewer utilities.
  • DSI Ignition – direct spark ignition – this term refers to the method of igniting the main burner on a propane fired appliance. The burner is lit with an electric spark and the flame is monitored by an electronic circuit board. This ignition system is used in refrigerators, furnaces and water heaters. There is now a version of stove tops that light the burners with a DSI ignition.
  • Dual Electrical System – RV equipped with lights, appliances which operate on 12-volt battery power when self-contained, and with a converter, on 110 AC current when in campgrounds or with an onboard generator.
  • Ducted AC – is air conditioning supplied through a ducting system in the ceiling. This supplies cooling air at various vents located throughout the RV.
  • Dump station – Usually a concrete pad with an inlet opening connected to an underground sewage system at a campground or other facility offering dumping service to RV travelers.
  • DW – Dry weight. The manufacturer’s listing of the approximate weight of the RV with no supplies, water, fuel or passengers.
  • Equalizing Hitch – A hitch that utilizes spring bars that are placed under tension to distribute a portion of the trailer’s hitch weight to the tow vehicle’s front axle and the trailer’s axles. The hitch is also known as a weight-distributing hitch.

F - H

  • Fresh water – Water suitable for human consumption.
  • Full hookup – Term for campground accommodations offering water, sewer/septic and electricity; also refers to a RV with the abilities to use ‘full-hookups’.
  • Full-timing – Living in one’s RV all year long. These RVers are known as full-timers.
  • Galley – The kitchen of an RV.
  • GAWR (Gross Axle Weight Rating) – The manufacturer’s rating for the maximum allowable weight that an axle is designed to carry. Gawr applies to tow vehicle, trailer, fifth-wheel and motorhome axles.
  • GCWR (Gross Combination Weight Rating) – The maximum allowable weight of the combination of tow vehicle and trailer/ fifth-wheel, or motorhome and dinghy. It includes the weight of the vehicle, trailer/fifth-wheel (or dinghy), cargo, passengers and a full load of fluids (fresh water, propane, fuel, etc.).
  • Generator – An electrical device powered by gasoline or diesel fuel, and sometimes propane, for generating 120-volt AC power.
  • Gray water – Used water that drains from the kitchen and bathroom sinks and the shower into a holding tank, called a gray water holding tank, that is located under the main floor of the RV.
  • GTWR (Gross Trailer Weight Rating) – Maximum allowable weight of a trailer, fully loaded with cargo and fluids.
  • GVWR (Gross Vehicle Weight Rating) – The total allowable weight of a vehicle, including passengers, cargo, fluids and hitch weight.
  • Hard-sided – RV walls made of aluminum or other hard surface.
  • Holding Tanks – Tanks that retain waste water when the RV unit is not connected to a sewer. The gray water tank holds wastewater from the sinks and shower; the black water tank holds sewage from the toilet.
  • Hookups – The ability of connecting to a campground’s facilities. The major types of hookups are electrical, water and sewer. If all three of these hookups are available, it is termed full hookup. Hookups may also include telephone and cable TV in some campgrounds.
  • House Battery – Battery or batteries in motorhome for operating the 12-volt system within the motorhome, separate from the chassis.

I - N

  • Inverter – A unit that changes 12-volt direct current to 110-volt alternating current to allow operation of computers, TV sets, and such when an RV is not hooked up to electricity.
  • Island Queen – A queen-sized bed with walking space on both sides.
  • Jackknife – 90% angle obtained from turning/backing fifth wheel or travel trailer with tow vehicle. Jackknifing a short bed truck towing a fifth wheel without the use of a slider hitch or extended fifth wheel pin box can result in damage to the truck cab or breaking out the back window of the truck cab from the truck and fifth wheel “colliding”.
  • Leveling – Positioning the RV in camp so it will be level, using ramps (also called levelers) placed under the wheels, built-in scissors jacks, or power leveling jacks.
  • LP Gas – Propane; abbreviation for liquefied petroleum gas, which is a gas liquefied by compression, consisting of flammable hydrocarbons and obtained as a by-product from the refining of petroleum or natural gas. Also called bottled gas, LPG (liquid petroleum gas) and CPG (compressed petroleum gas).
  • MH – Abbreviation for “motorhome”.
  • NCC (Net Carrying Capacity) – Maximum weight of all passengers (if applicable), personal belongings, food, fresh water, supplies — derived by subtracting the uvw from the gvwr.

P - R

  • Pop-out – Term for room or area that ‘pops-out’ for additional living space in RV. This type of expanded living area was more common before the technology of slide-out rooms became popular and available.
  • Popup/Pop-Up – Folding camping trailer.
  • Primitive camping – Also known as “dry camping”, boondocking. Camping without the modern convenience of full-hookup facilities of city/well water, sewer/septic and electricity. Primitive campers rely on ‘on-board’ systems for these conveniences; generator, batteries, stored water, etc.
  • Propane – LPG, or liquefied petroleum gas, used in RVs for heating, cooking and refrigeration. Also called bottle gas, for manner in which it is sold and stored.
  • Pull-through – A campsite that allows the driver to pull into the site to park, then pull out the other side when leaving, without ever having to back up.
  • Receiver – The portion of a hitch that permits a hitch bar or shank to be inserted. The receiver may be either 11/2-, 15/8- or 2-inch square; the smallest being termed a mini-hitch.
  • Reefer – Slang for “refrigerator”. Refrigerators are often found in either a “two way” or “three way” operating mode. Two way: has a gas mode and an AC mode. Three way: has a gas mode, AC mode, and 12v DC mode. The coolant used in RV refrigeration is ammonia. The two most common manufacturers of RV refrigerators are Norcold and Dometic.
  • Roof Air Conditioning – Air conditioning unit mounted on the roof of the RV.
  • RV – short for Recreation Vehicle, a generic term for all pleasure vehicles which contain living accommodations. Multiple units are RVs and persons using them are RVers.

S - T

  • Self-contained – An RV that needs no external connections to provide short-term cooking, bathing, and heating functions and could park overnight anywhere.
  • Shore cord – The external electrical cord that connects the vehicle to a campground electrical hookup.
  • Shore Power – Electricity provided to the RV by an external source other than the RV battery.
  • Sideout – A unit that slides open when the RV is parked to expand the living area.
  • Tail Swing – Motorhomes built on chassis with short wheelbases and long overhangs behind the rear axle are susceptible to tail swing when turning sharply. As the motorhome moves in reverse or turns a corner, the extreme rear of the coach can move horizontally and strike objects nearby (typically road signs and walls). Drivers need to be aware of the amount of tail swing in order to prevent accidents.
  • Tow Rating – The manufacturer’s rating of the maximum weight limit that can safely be towed by a particular vehicle. Tow ratings are related to overall trailer weight, not trailer size, in most cases. However, some tow ratings impose limits as to frontal area of the trailer and overall length. The vehicle manufacturer according to several criteria, including engine size, transmission, axle ratio, brakes, chassis, cooling systems and other special equipment, determines tow ratings.
  • Trailer Brakes – Brakes that are built into the trailer axle systems and are activated either by electric impulse or by a surge mechanism. The overwhelming majority of RVs utilize electric trailer brakes that are actuated when the tow vehicle’s brakes are operated, or when a brake controller is manually activated. Surge brakes utilize a mechanism that is positioned at the coupler, that detects when the tow vehicle is slowing or stopping, and activates the trailer brakes via a hydraulic system (typically used on boats).
  • Travel Trailer – Also referred to as “conventional trailers,” these types of rigs have an A-frame and coupler and are attached to a ball mount on the tow vehicle. Travel trailers are available with one, two or three axles. Depending upon tow ratings, conventional trailers can be towed by trucks, cars or sport-utility vehicles.

U - W

  • UVW (Unloaded Vehicle Weight) – Weight of the vehicle without manufacturer’s or dealer-installed options and before adding fuel, water or supplies.
  • Weight-Carrying Hitch – Also known as a “dead-weight” hitch, this category includes any system that accepts the entire hitch weight of the trailer. In the strictest sense, even a weight-distributing hitch can act as a load-carrying hitch if the spring bars are not installed and placed under tension.
  • Weight-Distributing Hitch – Also known as an “equalizing” hitch, this category includes hitch systems that utilize spring bars that can be placed under tension to distribute a portion of the trailer’s hitch weight to the tow vehicle’s front axle and the trailer’s axles.
  • Weights: – GAWR: Gross Axle Weight Rating. The maximum allowable weight each axle is designed to carry, as measured at the tires, therefore including the weight of the axle assembly itself. GAWR is established by considering the ratio of each of its components (tires, wheels, springs, and axle) and rating the axle on its weakest link. The GAWR assumes that the load is equal on each side. GCWR: Gross Combined Weight Rating. The maximum allowable combined weight of the tow vehicle and the attached towed vehicle. GCWR assumes both vehicles have functioning brakes, with exceptions in some cases for very light towed vehicles, normally less than 1,500 pounds. (check your chassis manual or towing guide). GVWR: Gross Vehicle Weight Rating. The maximum allowable weight of the fully loaded vehicle, including liquids, passengers, cargo, and tongue weight of any towed vehicle. NCC: Net Carrying Capacity. The maximum weight of all personal belongings, occupants, food, fresh water, LP gas, tools, dealer installed accessories, etc., that can be carried by the RV. (Technically, the GVWR less the UVW equals the NCC.) Payload Capacity. The maximum allowed weight that can be in or on a vehicle, including all cargo and accessories, fuel freshwater, propane, passengers and hitch loads. UVW: Unloaded Vehicle Weight. The weight of a vehicle as built at the factory with full fuel, engine (generator) oil and coolants. It does not include cargo, fresh water, LP gas, occupants, or dealer installed accessories. water (weight): 8.3 lbs. per gallon LP gas (weight): 4.5 lbs. per gallon driver (estimated weight): 200 lbs. passenger (estimated weight): 120 lbs. Gasoline: weighs 6.3 pounds per gallon Diesel fuel: weighs 6.6 pounds per gallon Propane: weighs 4.25 pounds per gallon
  • Wet Weight – Term used by RVers to describe the weight of a RV with all storage and holding tanks full. i.e., water, propane, etc.
  • Winterize – To prepare the RV for winter use or storage.