\Whap\, Whop \Whop\, v. i. [Cf. OE. quappen to palpitate,
E. quob, quaver, wabble, awhape, wap.]
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. --Bartlett.
Note: This word is used adverbially in the north of England,
      as in the United States, when anything vanishes, or is
      gone suddenly; as, whap went the cigar out of my mouth.

\Whap\, Whop \Whop\, v. t. [imp. & p. p. {Whapped}; p. pr.
& vb. n. {Whapping}.]
To beat or strike.

\Whap\, Whop \Whop\, n.
A blow, or quick, smart stroke.