An object placed against or under another, to support it; anything that supports.

(rugby) The player on either side of the hooker in a scrum.

Any of the seashells in the game of props.

(theater, film) An item placed on a stage or set to create a scene or scenario in which actors perform.

An item placed within an advertisement in order to suggest a style of living etc.

The propeller of an aircraft.

A proposition, especially on an election-day ballot.

(astronautics) propellant (“rocket fuel”)

(gambling, informal) Short for proposition player.

(Internet slang) A part of a plant reared for its multiplication.

(bodybuilding slang) Testosterone propionate.

(transitive, sometimes figurative) To support or shore up something.

(intransitive) To play rugby in the prop position.

(transitive, usually with "up" - see prop up) To position the feet of (a person) while sitting, lying down, or reclining so that the knees are elevated at a higher level.

To manually start the engine of a propeller-driven aircraft with no electric starter by pulling vigorously on one of the propeller blades using the hands, so that the propeller can catch ignition.