Etymology

The v. is formed on froþe (n.).

PGmc Ancestor

*fruþ- or *frauþ-

Proposed ON Etymon (OIcel representative)

froða (n., fem.) ‘froth’; frauð (n., neut.) ‘froth’ 
(ONP froða (sb.); frauð (sb.))

Other Scandinavian Reflexes

Far froða, froði, Icel froðe, Norw frode, froda, Dan fråde, Sw dial fruddo, frådas; Far froyður, Icel frauð, Norw fraud, Sw dial fraud, fröda, frau

OE Cognate

āfrēoþan (v.) ‘to froth’

Phonological and morphological markers

Summary category

C1

Attestation

Attested relatively uncommonly in ME from the late 14c. onwards from a variety of texts, incl. Chaucer.

Occurrences in the Gersum Corpus

Cl 1721

Bibliography

MED frō̆then (v.) , OED froth (v.) , HTOED ; see further froþe.