by 1942, noun ("a cowardly escape, an evasion") and verb ("sneak off, escape, give up without trying"), American English slang, perhaps from cop a plea (c. 1925) "plead guilty to lesser charges," which is probably from northern British slang cop "to catch" (a scolding, etc.); as in cop a feel "grope someone" (1930s); see cop (v.). Sense of "evade an issue or problem" is from 1960s.

c. 1600, "get along, succeed," from make (v.) + out (adv.). Sense of "obtain a clear understanding of" is from 1640s; that of "discern or discover visually" is by 1754; sense of "have sexual relations with" is attested by 1939.

"lose consciousness," 1915, from pass (v.) + out. Probably a weakened sense from earlier meaning "to die" (1899). Meaning "to distribute" is attested from 1926. Related: Passed out.