The Collaborative International Dictionary of English v.0.48:

Lacinia \La*cin"i*a\, n.; pl. L. Lacini[ae]. [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.
          [1913 Webster]

   2. (Zool.) The posterior, inner process of the stipes on the
      maxill[ae] of insects.
      [1913 Webster] Laciniate