[1] : The Collaborative International Dictionary of English v.0.48

whap \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.
   1913 webster

   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.
         1913 webster whap

[2] : The Collaborative International Dictionary of English v.0.48

whap \whap\, whop \whop\, v. t. imp.  p. p. whapped; p. pr.
    vb. n. whapping.
   to beat or strike.
   1913 webster whap
see also:
whapped whapping 

[3] : The Collaborative International Dictionary of English v.0.48

whap \whap\, whop \whop\, n.
   a blow, or quick, smart stroke.
   1913 webster whapper

[4] : WordNet (r) 2.0

whap
     v : hit hard syn: sock, bop, whop, bonk, bash
     also: whapping, whapped
see also:
sock bop whop bonk bash whapping 
whapped 

Whap >> W Words
Whap, definition of term: Whap
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