The story
- Proto-Germanic · derived from*fruþǭ
- Old Norse · derived fromfroða
- Middle English · inherited fromfroth
- English todayfroth
From Middle English froth, frooth, froþ, likely a borrowing from Old Norse froða, from Proto-Germanic *fruþǭ; Old English āfrēoþan (“to foam, froth”) is from same Germanic root. Verb attested from late 14th century. Compare Swedish fradga.
Etymology from Wiktionary, CC BY-SA 4.0.