idiosyncrasy (n.)youdaoicibaDictYouDict[idiosyncrasy 词源字典]
c. 1600, from French idiosyncrasie, from Greek idiosynkrasia "a peculiar temperament," from idios "one's own" (see idiom) + synkrasis "temperament, mixture of personal characteristics," from syn "together" (see syn-) + krasis "mixture" (see rare (adj.2)). Originally in English a medical term meaning "physical constitution of an individual." Mental sense first attested 1660s.[idiosyncrasy etymology, idiosyncrasy origin, 英语词源]