unkindness (n.)youdaoicibaDictYouDict[unkindness 词源字典]
c. 1300, "state or character of being unkind, lack of natural regard or proper consideration," from un- (1) "not" + kindness (n.), or from unkind (adj.) + -ness. Meaning "an unkind act" is from c. 1500.[unkindness etymology, unkindness origin, 英语词源]