Knap

Webster's Practical Dictionary- A Practical Dictionary of the Englih Language · 1884 · p. 228

nap, v. t. [knapped (napt), -ping.] bite off; to strike with a loud noise; to snap. To make a short, sharp sound; to snap. — Knap's ack, n. A case for food, clothing, etc., borne on the back by soldiers, travelers, etc. Knar, Knarl. See Gnarl.