The story
- Proto-Indo-European*(s)poH(y)-
- Proto-Indo-European*(s)póHy-mos
- Latinspūma
- Proto-Indo-European*h₃ed-
- Proto-Indo-European*h₃édosder.?
- Latinspūmōsus
- Middle Englishspumous
- English todayspumous
From Middle English spumous, from Latin spūmōsus.
Etymology from Wiktionary, CC BY-SA 4.0.