Whap

(hwŏp), v. i. [See infra.] To throw one's self quickly, or by an abrupt motion; to turn suddenly; as, she whapped down on the floor; the fish whapped over. [Written also whop.] Bartlett.

☞ The word is used adverbially in the north of England, as in the U. S., when any thing vanishes, or is gone suddenly; as, whap went the cigar out of my mouth.