repetition (n.)youdaoicibaDictYouDict[repetition 词源字典]
early 15c., "act of saying over again," from Old French repetition and directly from Latin repetitionem (nominative repetitio) "a repeating," noun of action from past participle stem of repetere "do or say again" (see repeat (v.)). Of actions, attested from 1590s; specifically in physical fitness from 1958.[repetition etymology, repetition origin, 英语词源]