plica

A fold or crease, especially of skin or other tissue.
Polish plait, plica polonica, or plica neuropatica: a disease of the hair in which it becomes twisted and matted together.
A diseased state in plants in which there is an excessive development of small entangled twigs, instead of ordinary branches.
The bend of the wing of a bird.
A neume, in the form of a tail at the end of a ligature, indicating an additional note.