quaintyoudaoicibaDictgodict[quaint 词源字典]
quaint: [13] Quaint was once a more wholehearted term of approval than it is now. In Middle English it meant ‘clever’ or ‘finely or skilfully made’. Its current sense ‘pleasantly curious’ did not emerge until the 18th century. It comes via Old French coint from Latin cognitus ‘known’, the past participle of cognōscere ‘know’ (source of English recognize). The word’s meaning evolved in Old French via the notion of someone who ‘knows’ about something, and hence is an expert at it or is skilful in doing it.
=> cognition, recognize[quaint etymology, quaint origin, 英语词源]
quaint (adj.)youdaoicibaDictgodict
c. 1200, cointe, "cunning, ingenious; proud," from Old French cointe "knowledgeable, well-informed; clever; arrogant, proud; elegant, gracious," from Latin cognitus "known, approved," past participle of cognoscere "get or come to know well" (see cognizance). Modern spelling is from early 14c.

Later in English, "elaborate, skillfully made" (c. 1300); "strange and clever" (mid-14c.). Sense of "old-fashioned but charming" is first attested 1795, and could describe the word itself, which had become rare after c. 1700 (though it soon recovered popularity in this secondary sense). Related: Quaintly; quaintness.