Where does “ທຳ” come from?

ທຳ (Lao) comes from Pali dhamma, from Sanskrit धर्म, from Proto-Indo-Iranian dʰármas, from Proto-Indo-European dʰer- — to support; to hold.

ທຳ (Lao): to do; to make; to perform; dharma; virtue,...

Definitions

Step	Language	Word	Meaning
1	Pali	dhamma	truth, righteousness; doctrine, teachings;...
2	Sanskrit	धर्म	morality, virtue, moral code, good deed, good...
3	Proto-Indo-Iranian	dʰármas	—
4	Proto-Indo-European	dʰer-	to support; to hold