One of two sets of wheels under a locomotive or railcar; also, a structure with axles and wheels under a locomotive, railcar, or semi which provides support and reduces vibration for the vehicle.
A standard of performance set up as a mark to be aimed at in competition.
A set of wheels attached to one of an aircraft's landing gear, or the structure connecting the wheels in one such set.
A low, hand-operated truck, generally with four wheels, used for transporting objects or for riding on as a toy; a trolley.
An unidentified aircraft, especially as observed as a spot on a radar screen and suspected to be hostile.
A piece of dried mucus in or removed from the nostril.
A score of one over par on a hole.
A marijuana cigarette; a joint.
A ghost, goblin, or other hostile supernatural creature.
A chassis or framework-like structure underneath a railroad car to which wheel axles (and, hence, wheels) are attached through bearings. (Not to be confused with railway truck or railtruck, which are British English synonyms of railroad car)