Cart: a short, simple word to signify "wheeled conveyance"; specifically one or more wheels attached to a load-bearing platform in a manner to facilitate moving a load from one position to another. Common examples of carts (wheeled conveyances) include: roller skates, unicycles, Johnson bars (pry dollies), skateboards, automobiles, trucks, locomotives and rail cars, bicycles, motorcycles, tricycles, scooters, rickshaws, wheelbarrows, airplanes, tanks and Caterpillar tractors and other tracked vehicles, trams, and dollies.
Edge cases that might be included: roller track conveyor system, railroad roundhouse, potter's wheel, and lazy susan. Forms of conveyance excluded (no wheels): elevators, sleds, litters, skis, ice skates, barges and other water-borne vessels, float-planes, aerial trams, and lift gondolas.