Webster's 1828 Dictionary
WHAP
n.A blow. [Vulgar. ] [See Awhape. ]
WHAPPER
n.Something uncommonly large of the kind. So thumper is connected with thump, to strike with a heavy blow. [Vulgar. ]
Webster's 1913 Dictionary
WHAP; WHOP
Whap, Whop, v. i. Etym: [Cf. OE. quappen to palpitate, E. quob, quaver, wabble, awhape, wap. ]
Defn: 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
Whap, Whop, v. t. [imp. & p. p. Whapped; p. pr. & vb. n. Whapping.]
Defn: To beat or strike.
WHAP; WHOP
WHAP; WHOP Whap, Whop, n.
Defn: A blow, or quick, smart stroke.
WHAPPER; WHOPPER
Whap "per, Whop "per, n. Etym: [See Whap. ]
Defn: Something uncommonly large of the kind; something astonishing; -- applied especially to a bold lie. [Colloq. ]
WHAPPING; WHOPPING
WHAPPING; WHOPPING Whap "ping, Whop "ping, a.
Defn: Very large; monstrous; astonishing; as, a whapping story. [Colloq. ]
New American Oxford Dictionary
whap
whap |(h )wap (h )wæp | ▶verb ( whaps, whapping, whapped ) & noun variant spelling of whop.
Oxford Dictionary
whap
whap ▶verb ( whaps, whapping, whapped ) & noun chiefly N. Amer. variant spelling of whop.
The Wordsmith Dictionary