c.1300, "a regarding, heeding, observation," from O.N.Fr. reward, variant of O.Fr. reguard (see regard). Meaning "repayment for some service" is from mid-14c.
early 14c., from O.N.Fr. rewarder, variant of O.Fr. regarder "take notice of, regard, watch over," from re-, intensive prefix, + garder "look, heed, watch" (see guard). Originally any form of requital.