Meaning

verb strike sharply

verb break a small piece off from

originThe verb is derived from Late Middle English knappen (“to strike (something)”); further etymology uncertain, probably related to Middle Dutch knappen, cnappen (“to break (something) with a sharp sound, snap; to crack or crackle”) (modern Dutch knappen), probably ultimately onomatopoeic. The noun is derived from Late Middle English knap, knappe (“sharp blow, strike”); further etymology uncertain,…

Etymology from Wiktionary, CC BY-SA 3.0