The story
- Proto-Celtic · derived from*moltos“ram, wether”
- Gaulish · derived from*multon-
- Vulgar Latin · derived frommoltō
- Old French · derived frommouton“sheep”
- Middle English · inherited frommotoun
- English todaymutton
From Middle English motoun, moton, from Old French mouton (“sheep”), from Vulgar Latin moltō, from Gaulish *multon-, from Proto-Celtic *moltos (“ram, wether”). Doublet of mouton.
Etymology from Wiktionary, CC BY-SA 4.0.