insensitive (adj.)youdaoicibaDictYouDict[insensitive 词源字典]
c. 1600, "having little or no reaction to what is perceived by one's senses," from in- (1) "not, opposite of" + sensitive. For sense, see insensate. Meaning "without consideration for the feelings of others" attested by 1975. Related: Insensitively.[insensitive etymology, insensitive origin, 英语词源]