- impassive (adj.)
[impassive 词源字典]
- 1660s, "not feeling pain," from assimilated form of in- "not, opposite of" (see in- (1)) + passive. Meaning "void of emotions" is from 1690s. Related: Impassively; impassiveness (1640s).[impassive etymology, impassive origin, 英语词源]