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.

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.

"secret agreement for fraudulent or harmful purposes," late 14c., from Old French collusion and directly from Latin collusionem (nominative collusio) "act of colluding," from colludere, from assimilated form of com "with, together" (see com-) + ludere "to play" (see ludicrous). "The notion of fraud or underhandedness is essential to collusion" [Fowler].

"deceive, impose upon, mislead the mind or judgment of," c. 1400, from Latin deludere "to play false; to mock, deceive," from de- "down, to one's detriment" (see de-) + ludere "to play" (see ludicrous). Related: Deluded; deluding.

Mislead means to lead wrong, whether with or without design. Delude always, at least figuratively, implies intention to deceive, and that means are used for that purpose. We may be misled through ignorance and in good faith, but we are deluded by false representations. A person may delude himself. [Century Dictionary]

1530s, "delude, make a fool of," from Latin eludere "finish play, win at play; escape from or parry (a blow), make a fool of, mock, frustrate; win from at play," from assimilated form of ex "out, away" (see ex-) + ludere "to play" (see ludicrous). Sense of "evade" is first recorded 1610s in a figurative sense, 1630s in a literal one. Related: Eluded; eludes; eluding.

early 15c., "to trick, deceive; treat with scorn or mockery," from Latin illudere "to make sport of, scoff at, mock, jeer at," from assimilated form of in- "in, into" (from PIE root *en "in") + ludere "to play" (see ludicrous).

mid-14c., "mockery, scorning, derision;" late 14c., "act of deception; deceptive appearance, apparition; delusion of the mind," from Old French illusion "a mocking, deceit, deception" (12c.), from Latin illusionem (nominative illusio) "a mocking, jesting, jeering; irony," from past-participle stem of illudere "mock at," literally "to play with," from assimilated form of in- "at, upon" (from PIE root *en "in") + ludere "to play" (see ludicrous). Sense of "deceptive appearance" first developed in Church Latin. Related: Illusioned "full of illusions" (1920).

1590s, from French illusorie, from Late Latin illusorius "ironical, of a mocking character," from illus-, past participle stem of Latin illudere "mock, jeer at, make fun of," literally "play with," from assimilated form of in- "at, upon" (from PIE root *en "in") + ludere "to play" (see ludicrous).

formerly also enterlude, c. 1300, from Old French entrelude and directly from Medieval Latin interludium "an interlude," from Latin inter "between" (see inter-) + ludus "a play" (see ludicrous). Originally the term for farcical episodes ("generally short and coarse" - Century Dictionary) drawn from real life introduced between acts of long mystery or morality plays. In 17c.-18c. it meant "popular stage play;" transferred (non-dramatic) sense of "interval in the course of some action" is from 1751. Related: Interludial.

"spontaneously playful," 1940, a term in psychiatry, from French ludique, from Latin ludere "to play" (see ludicrous).