1540s, "metaphor, parable" (a sense now obsolete); 1550s, "word-play, joke;" 1610s as "passing or casual reference," from Latin allusionem (nominative allusio) "a playing with, a reference to," noun of action from past-participle stem of alludere "to play, jest, make fun of," from ad "to" (see ad-) + ludere "to play" (see ludicrous). An allusion is never an outright or explicit mention of the person or thing the speaker seems to have in mind.

1953 (implied in underwhelming), a facetious play on overwhelm, with under. Related: Underwhelmed; underwhelmingly.

of a play, "consisting of a single act," 1888, from one + act (n.).

1734, "a piece of lively play," from romp (v.). From 1706 as "a wanton, merry, rude girl," in this sense perhaps a variant of ramp (n.2) suggested by the notion of "girl who indulges in boisterous play."

c. 1600, "to play the clown onstage," from clown (n.); colloquial sense of "to behave inappropriately" (as in clown around, 1932) is attested by 1928, perhaps from the theatrical slang sense of "play a (non-comical) part farcically or comically" (1891). Related: Clowned; clowning.

"to play, sport," Old English lacan (see lark (n.2)).

in natural history, "freak of nature," 1660s, a Latin phrase, from lusus "a play," from stem of ludere "to play" (see ludicrous) + genitive of natura (see nature (n.)). Originally of fossils, before there was a scientific basis for understanding their existence.

"amorous play with the feet" [OED], 1944, from foot (n.). Footie in the same sense is from 1935.

1530s, "to mock" (transitive, now obsolete), from French alluder or directly from Latin alludere "to play, make fun of, joke, jest," also of waves lapping the shore, from assimilated form of ad "to" (see ad-) + ludere "to play" (see ludicrous). The meaning "make an indirect reference, point in passing" is from 1530s. Related: Alluded; alluding.

1941, originally a film title, from ice (n.) + a punning play on escapade.