Merriam-Webster's Collegiate® Dictionary, 11th Edition
-WARD
I. adjective suffix also -wards see: worth that moves, tends, faces, or is directed toward , that occurs or is situated in the direction of ,
II. adverb suffix or -wards
Etymology: -ward from Middle English, from Old English -weard, from -weard, adjective suffix; -wards from Middle English, from Old English -weardes, genitivesingular neuter of -weard, adjective suffix in a (specified) spatial or temporal direction , toward a (specified) point, position, or area