What does "nap" mean?

Additional senses

1. 2.A short sleep; a doze; a siesta. Cowper.
2. 3.Woolly or villous surface of felt, cloth, plants, etc.; an external covering of down, of short fine hairs or fibers forming part of the substance of anything, and lying smoothly in one direction; the pile; -- as, the nap of cotton flannel or of broadcloth.
3. 4.pl. The loops which are cut to make the pile, in velvet. Knight.
4. 5.To raise, or put, a nap on.