Noah Webster
Knap
KNAP, noun nap. A protuberance; a swelling. [Little Used. See Knob.]
KNAP, verb transitive nap. [See Knab.]
1. To bite; to bite off; to break short. [Little Used.]
2. To strike with a sharp noise. [Little Used.]
KNAP, verb intransitive nap. To make a short, sharp sound.