From Wiktionary, the free dictionary
Cognate with Fula kosam (“milk”), Serer fosoow.
soow
- curdled milk, buttermilk
- breastmilk, mother's milk
- Fal, Arame, Santos, Rosine, Doneux, Jean Léonce (1990) Dictionnaire wolof-français, Paris: Éditions KARTHALA, →ISBN, page 206