Rearwards comes from rearward + adverbial -s; rear from Old French rere ('behind'), from Latin retro ('back'), with the Old English directional suffix -weard. The historical chain includes Latin retro and Old English -weard. The quoted older senses, "behind" and "back", supply the semantic anchors for rearwards. The formation is best read as suffixal, compound, and borrowed: the word rearwards carries its older form-history into a compact English lexical shape. In present English it is used as a adv, "toward the back or rear". Related English forms include rear and rearward. The result is a adv whose etymology preserves both the older form and the later English specialization.