Where does “mốch” come from?

mốch (Muong) comes from Proto-Vietic moːc, from Proto-Mon-Khmer muuj — one.

mốch (Muong): one

Definitions

Step	Language	Word	Meaning
1	Proto-Vietic	moːc	one
2	Proto-Mon-Khmer	muuj	one

mốch — Etymology, Origin & Word History | Etymology Explorer