a support placed beneath or against something to keep it from shaking or falling
"The carpenter used a wooden prop beneath the loose staircase railing to prevent it from collapsing during repairs."
a propeller that rotates to push against air
"The aircraft's main prop spun rapidly, generating enough thrust to lift it off the runway."
An object placed against or under another, to support it; anything that supports.
"The engineers replaced the old propellant with a more efficient type of rocket fuel to increase the satellite's thrust."
An item placed on a stage or set to create a scene or scenario in which actors perform.
The propeller of an aircraft.
A proposition, especially on an election-day ballot.
propellant (“rocket fuel”)
In plain English: A prop is an object used to help someone act out a scene or make something look real during a performance.
"She used an old chair to prop up her laptop while she worked at the cafe."
Usage: Use "prop" as an uncountable noun when referring generally to the collective items used by actors during a performance. When specifying individual objects like chairs or books, treat them as countable nouns (e.g., "a prop," "two props"). Avoid confusing this term with "property," which is often reserved for formal theater contexts but can sometimes be interchangeable in casual conversation depending on regional usage.
To support or shore up something.
"The pilot leaned out over the wing and physically propped the airplane's engine by grabbing and spinning the large wooden blade until it caught fire."
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.
In plain English: To prop something is to hold it up so it doesn't fall over.
"He propped his chair up against the wall to stabilize it before sitting down."
The word "prop" comes to English via the Middle English proppe, which originally meant a support or something used to hold up vines and plants. It was borrowed from Middle Dutch, where it carried similar meanings of both structural supports and bottle stoppers.