a.

1. 左的
2. 使用左手的
3. 左旋的

n.

1. 左撇子

adj.

1. of or on the left side or the left hand. The opposite of dextral.
   ▸left-handed.
2. Geology  relating to or denoting a strike-slip fault in which the motion of the block on the further side of the fault is towards the left.
3. Zoology  (of a spiral mollusc shell) with whorls rising to the left and coiling clockwise.

n.