英语词源字典 - 在线词源网站

advantageous (adj.)[advantageous 词源字典]: 1590s, formed in English from advantage, or else from French avantageux (15c.), from avantage (see advantage). Related: Advantageously; advantageousness.[advantageous etymology, advantageous origin, 英语词源]
cloak (n.): late 13c., "long, loose outer garment," from Old North French cloque (Old French cloche, cloke) "travelling cloak," from Medieval Latin clocca "travelers' cape," literally "a bell," so called from the garment's bell-like shape (the word is thus a doublet of clock (n.1)). An article of everyday wear in England through 16c., somewhat revived 19c. as a fashion garment. Cloak-and-dagger (adj.) attested from 1848, said to be ultimately translating French de cape et d'épée, suggestive of stealthy violence and intrigue.
Other "cloak and dagger pieces," as Bouterwek tells us the Spaniards call their intriguing comedies, might be tried advantageously in the night, .... ["Levana; or the Doctrine of Education," English translation, London, 1848]
disadvantageous (adj.): c. 1600; see disadvantage (n.) + -ous. Related: Disadvantageously.
purchase (n.): c. 1300, purchas, "acquisition, gain;" also, "something acquired or received, a possession; property, goods;" especially "booty, spoil; goods gained by pillage or robbery" (to make purchase was "to seize by robbery"). Also "mercenary soldier, one who fights for booty." From Anglo-French purchace, Old French porchaz "acquisition, gain, profit; seizing, plunder; search pursuit, effort," from Anglo-French purchaser, Old French porchacier (see purchase (v.)).

From early 14c. as "endeavor, effort, exertion; instigation, contrivance;" late 14c. as "act of acquiring, procurement." Meaning "that which is bought" is from 1580s. The sense of "hold or position for advantageously applying power" (1711) is extended from the nautical verb meaning "to haul or draw (especially by mechanical power)," often used in reference to hauling up anchors, attested from 1560s. Wif of purchase (early 14c.) was a term for "concubine."