La*cin"i*a (?), n.; pl. L. Laciniæ (#). [L., the lappet or flap of a garment.] 1. (Bot.) (a) One of the narrow, jagged, irregular pieces or divisions which form a sort of fringe on the borders of the petals of some flowers. (b) A narrow, slender portion of the edge of a monophyllous calyx, or of any irregularly incised leaf.

2. (Zoöl.) The posterior, inner process of the stipes on the maxillæ of insects.