(organic chemistry) Denoting the presence of 3 carbon atoms in the parent chain when forming names of organic compounds.

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.

(gambling, informal) Short for proposition player.

(astronautics) propellant (“rocket fuel”)

(transitive, sometimes figuratively) To support or shore up something. / (intransitive) To play rugby in the prop position.

The propeller of an aircraft.

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. / One 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.

A proposition, especially on an election-day ballot.

(law) Abbreviation of property. / Alternative form of prop.