rep (1)

mid-14c., reputacioun, "credit, good reputation, esteem;" late 14c. in the general sense of "opinion, estimation," good or bad; from Old French reputation, reputacion, and directly from Latin reputationem (nominative reputatio) "a reckoning, consideration, a thinking over," noun of action from past-participle stem of reputare "reflect upon, reckon, count over."

This is from re-, here perhaps "repeatedly" (see re-), + putare "to judge, suppose, believe, suspect," originally "to clean, trim, prune" (from PIE root *pau- (2) "to cut, strike, stamp").

early 15c., repeticioun, "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 or events recurring or done again, attested from 1590s; specifically in physical fitness from 1958. Related: Repetitions.