Longman Dictionary of Contemporary English - prop

~1 v propped, propping T always + adv/prep to support something by leaning it against something, or by putting something else under, next to, or behind it  (prop sth against/on)  (He propped his bike against a tree. | prop sth open)  (Give me something to prop the door open.) prop sth up phr v 1 to prevent something from falling by putting something against it or under it  (The builders are trying to prop up the crumbling walls of the church.) 2 if a government props up another government it helps it with financial or military support so that it can continue to exist 3 prop yourself up to stand or sit straight by leaning against something ~2 n 1 an object placed under or against something to hold it in a position  (- see also pit prop) 2 a small object such as a book, weapon etc used by actors in a play or film 3 informal a short form of the word propeller 4 something or someone that helps you to feel strong, or that an idea or system needs in order to exist  (The big house and the car were all props to his ego.)