1811, "courageous," originally of fist fights, denoting a manful contest without fake falls, from the verbal phrase (early 12c. in sense "rise to one's feet"), from stand (v.) + up (adv.). To stand up "hold oneself against an opponent" is from c. 1600; as stand up to in the same sense from 1620s. To stand up for "defend the cause of" is from c. 1600. To stand (someone) up "fail to keep an appointment" is attested from 1902. Stand-up comic first attested 1966. Catch-phrase will the real _______ please stand up? is from the popular CBS game show "To Tell the Truth," which debuted in 1956.
