treacheryyoudaoicibaDictYouDict[treachery 词源字典]
treachery: [13] Despite the passing resemblance, treachery has no etymological connection with traitor or treason. In fact, its closest English relative is trick. The word was borrowed from Old French trecherie, a derivative of trichier ‘cheat’ (source of English trick).
=> trick[treachery etymology, treachery origin, 英语词源]
trickyoudaoicibaDictYouDict
trick: [15] Trick comes from Old French trique, a variant of triche, which was derived from the verb trichier ‘cheat’ (source of English treachery). And this in turn probably came from Latin trīcarī ‘make difficulties, play tricks’ (source also of English extricate [17] and intricate [15]), a derivative of trīcae ‘difficulties, tricks’, whose origins are unknown. Tricky dates from the 18th century, its use for ‘difficult’ from the end of the 19th century.
=> extricate, intricate, treachery
treacherous (adj.)youdaoicibaDictYouDict
early 14c., from Old French trecheros, tricheros "deceitful" (12c.), from trecheor, tricheor "cheat, deceiver, liar, impostor, trickster," agent noun from trechier, trichier "to cheat, trick" (see trick (n.)). Figuratively, of things, from c. 1600. Related: Treacherously; treacherousness. Middle English had treacher "deceiver, cheat, traitor."
trick (n.)youdaoicibaDictYouDict
early 15c., "a cheat, a mean ruse," from Old North French trique "trick, deceit, treachery, cheating," from trikier "to deceive, to cheat," variant of Old French trichier "to cheat, trick, deceive," of uncertain origin, probably from Vulgar Latin *triccare, from Latin tricari "be evasive, shuffle," from tricæ "trifles, nonsense, a tangle of difficulties," of unknown origin.

Meaning "a roguish prank" is recorded from 1580s; sense of "the art of doing something" is first attested 1610s. Meaning "prostitute's client" is first attested 1915; earlier it was U.S. slang for "a robbery" (1865). To do the trick "accomplish one's purpose" is from 1812; to miss a trick "fail to take advantage of opportunity" is from 1889; from 1872 in reference to playing the card-game of whist, which might be the original literal sense. Trick-or-treat is recorded from 1942. Trick question is from 1907.