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