Where does “so le trong” come from?

so le trong (Vietnamese) comes from Vietnamese trồng, from Proto-Vietic k-lɔːŋ, from Proto-Mon-Khmer kluuŋ — inside, middle.

so le trong (Vietnamese): alternate; being Z angles

Definitions

Step	Language	Word	Meaning
1	Vietnamese	trồng	to plant
2	Proto-Vietic	k-lɔːŋ	clear; limpid; inside
3	Proto-Mon-Khmer	kluuŋ	inside, middle

so le trong — Etymology, Origin & Word History | Etymology Explorer