uninterested (adj.)youdaoicibaDictYouDict[uninterested 词源字典]
1640s, "unbiased," from un- (1) "not" + past participle of interest (v.). It later meant "disinterested" (1660s); sense of "unconcerned, indifferent" is recorded from 1771. This is the correct word for what often is miscalled disinterested.[uninterested etymology, uninterested origin, 英语词源]