"practice or hobby of dressing as a character from a movie, book, or video game, especially one from Japanese manga and anime," 1993, according to Merriam-Webster, from costume (n.) + play (n.), based on a Japanese word formed from the same English elements and alleged to date from 1983. Also used as a verb.
Middle English pleiere, from Old English plegere "one who takes part in pastimes or amusements," agent noun from play (v.). Stage sense of "performer of plays, actor," also "one who performs on a musical instrument" are from c. 1400. Meaning "contestant in field or martial games" is from early 15c.; of table games, late 14c. As a pimp's word for himself (also playa), attested from 1974 (sexual senses of play (v.) go back to 13c.). Player-piano is attested from 1901.
"to emphasize (something) too much," 1933, a metaphor from card games, in to overplay (one's) hand, "to spoil one's hand by bidding in excess of its value" (1926), from over- + play (v.). Earlier (from 1819) in a theatrical sense, "act (a part) with an extravagant and unnatural manner." Middle English had overpleien in the sense of "to outplay, defeat." Related: Overplayed; overplaying.
by 1921 in sexual sense, from fore- + play (n.); Freud's Vorlust was translated earlier as fore-pleasure (Brill, 1910). A more direct translation from the German would be thwarted by the sense drift in English lust (n.). Earlier as a theatrical term:
In fact the poem which Mr. Brooks has translated is but the "prologue to the swelling theme," the fore-play to the actual drama of Faust. [The Christian Examiner and Religious Miscellany, Jan.-May 1857]