Where does “গৌড়” come from?

গৌড় (Bengali) comes from Sanskrit गौड, from Sanskrit गुड, from Proto-Dravidian *kuṭV.

Ancestry of “গৌড়”, step by step

Step	Language	Word	Meaning
1	Sanskrit	गौड	made of sugar or molasses; of or relating to the...
2	Sanskrit	गुड	sugar which forms itself into lumps, dry sugar,...
3	Proto-Dravidian	*kuṭV	—