The Collaborative International Dictionary of English v.0.48:
Leftward \Left"ward\ (-w[~e]rd), adv.
Toward or on the left side.
[1913 Webster]
Rightward and leftward rise the rocks. --Southey.
[1913 Webster]
Moby Thesaurus II by Grady Ward, 1.0:
23 Moby Thesaurus words for "leftward":
anticlockwise, aport, clockwise, counterclockwise, earthward,
heavenward, homeward, landward, larboard, leeward, left,
leftwardly, leftwards, on the left, port, rightward, seaward,
sinister, sinistrad, sinistrally, to the left, widdershins,
windward