Where does “k-nɛːŋ” come from?

k-nɛːŋ (Proto-Vietic) comes from Proto-Mon-Khmer gnaiŋ.

Ancestry of “k-nɛːŋ”, step by step

Step	Language	Word	Meaning
1	Proto-Mon-Khmer	gnaiŋ	—

k-nɛːŋ — Etymology, Origin & Word History | Etymology Explorer