a. 1. Of or pertaining to the left, inclining to the left; sinistrous; -- opposed to dextral. [ 1913 Webster ]
2. (Zool.) Having the whorls of the spire revolving or rising to the left; reversed; -- said of certain spiral shells. [ 1913 Webster ]
n. The quality or state of being sinistral. [ 1913 Webster ]
adv. Toward the left; in a sinistral manner. J. Le Conte. [ 1913 Webster ]