reflexive (adj.)youdaoicibaDictYouDict[reflexive 词源字典]
1580s, "reflective, capable of bending or turning back," from Medieval Latin reflexivus, from Late Latin reflexus (see reflect). Meaning "of the nature of a reflex" is from 1839 (implied in reflexively). Grammatical sense from 1837. Related: Reflexiveness; reflexivity.[reflexive etymology, reflexive origin, 英语词源]