Etymology

Probably formed from the v. wapped.

PGmc Ancestor

(1) *wap-

Proposed ON Etymon (OIcel representative)

vappa (v.) ‘to waddle’ 
(ONP (1) vappa (vb.))

Other Scandinavian Reflexes

(1) Far vappa, Icel vappa, Dan dial vappe, Sw dial vapp

OE Cognate

Phonological and morphological markers

Summary category

DD1c

Attestation

Mainly N and alliterative, with a handful of exceptions (inc. a1450(c1400) Wor.Serm.(Wor F.10), (1469) Paston).

Occurrences in the Gersum Corpus

Gaw 2249; Pat 499; WA 3040, 4142, 5318

Bibliography

MED wap (n.) , OED wap (n.1) , HTOED , Dance wap