Where does “ဟံသာဝတီ” come from?

ဟံသာဝတီ (Burmese) comes from Mon ဟံသာဝတဳ, from Pali ဟံသော, from Pali haṃsāvatī.

Ancestry of “ဟံသာဝတီ”, step by step

Step	Language	Word	Meaning
1	Mon	ဟံသာဝတဳ	—
2	Pali	ဟံသော	—
3	Pali	haṃsāvatī	—