iteration (n.)youdaoicibaDictYouDict[iteration 词源字典]
late 15c., from Latin iterationem (nominative iteratio) "repetition," noun of action from past participle stem of iterare "do again, repeat," from iterum "again," from PIE *i-tero-, from pronominal root *i- (see yon). [iteration etymology, iteration origin, 英语词源]