undefiled (adj.)youdaoicibaDictYouDict[undefiled 词源字典]
c. 1300, undefylde, from un- (1) "not" + past participle of defile (v.). Originally of morals; sexual sense is attested from mid-15c. Physical sense of "not made dirty" is from 1580s. [undefiled etymology, undefiled origin, 英语词源]