Where does “muco-” come from?

muco- (English) comes from Latin mūcus, from Proto-Italic moukos, from Proto-Indo-European mew-k- — slimy, slippery; slip, slime.

muco- (English): mucus

Definitions

Step	Language	Word	Meaning
1	Latin	mūcus	—
2	Proto-Italic	moukos	—
3	Proto-Indo-European	mew-k-	slimy, slippery; slip, slime

muco- — Etymology, Origin & Word History | Etymology Explorer