||Pli"ca (?), n. [LL., a fold, fr. L. plicare to fold. See Ply, v.] 1. (Med.) A disease of the hair (Plica polonica), in which it becomes twisted and matted together. The disease is of Polish origin, and is hence called also Polish plait. Dunglison.

2. (Bot.) A diseased state in plants in which there is an excessive development of small entangled twigs, instead of ordinary branches.

3. (Zoöl.) The bend of the wing of a bird.