Words related to re-
c. 1300, rewarden, "to grant, bestow;" early 14c. "to give as prize or compensation," from Anglo-French and Old North French rewarder "to regard, reward" (Old French regarder) "take notice of, regard, watch over." This is from re-, here perhaps an intensive prefix (see re-), + warder "look, heed, watch," from Frankish or some other Germanic language, from Proto-Germanic *wardon "to guard" (from PIE root *wer- (3) "perceive, watch out for").
Originally any form of requital, good or bad, for service or evil-doing. A doublet of regard (v.), reward was used 14c.-15c. in the senses now given to that word: "look at; care about; consider." Related: Rewarded; rewarding.
word-forming element of Latin origin meaning "backwards; behind," from Latin retro (prep.) "backward, back, behind," usually in reference to place or position, rarely of time, "formerly, in the past," probably originally the ablative form of *reteros, based on re- "back" (see re-).
L. retro stands to re- as intro, "in, within"; to in, "in," and as citro, "hither," stands to cis, "on this side." [Klein]
Common in combinations in post-classical Latin (the classical equivalent was post-). Active in English as a word-forming element from mid-20c.