repeatyoudaoicibaDictYouDict[repeat 词源字典]
repeat: [14] The -peat of repeat comes ultimately from Latin petere ‘go to, seek’, which has also given English appetite, compete, impetuous, perpetual [14], petition [14], and petulant [16]. Addition of the prefix re- ‘back, again’ produced repetere ‘go back to’, which reached English via Old French repeter.
=> appetite, compete, impetuous, perpetual, petition, petulant[repeat etymology, repeat origin, 英语词源]
repeat (v.)youdaoicibaDictYouDict
late 14c., "to say what one has already said," from Old French repeter "say or do again, get back, demand the return of" (13c., Modern French répéeter), from Latin repetere "do or say again; attack again," from re- "again" (see re-) + petere "to go to; attack; strive after; ask for, beseech" (see petition (n.)).

Meaning "say what another has said" is from 1590s. As an emphatic word in radio broadcasts, 1938. Meaning "do over again" is from 1550s; specific meaning "to take a course of education over again" is recorded from 1945, American English. Related: Repeated; repeating.
repeat (n.)youdaoicibaDictYouDict
mid-15c., of music passages, from repeat (v.). From 1937 of broadcasts.