Where does “伊洛瓦底” come from?

伊洛瓦底 (Chinese) comes from Burmese ဧရာဝတီ, from Sanskrit इरावती — granting drink or refreshment.

Ancestry of “伊洛瓦底”, step by step

Step	Language	Word	Meaning
1	Burmese	ဧရာဝတီ	—
2	Sanskrit	इरावती	granting drink or refreshment