Where does “Bengali” come from?

Bengali comes from Hindi बंगाली, derived from Sanskrit -इन् and -इक suffixes attached to a Proto-Indo-European root -iHnos and -no-.

Bengali (English): Of, from or pertaining to Bengal or the Bengalis;...

Definitions

Bengali traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	English	Bengal	A short-haired domestic cat breed, which...
2	Portuguese	Bengala	Bengal
3	Persian	بنگاله	—
4	Middle Bengali	বাঙ্গালা	Bengal
5	Sanskrit	वङ्गाल	—

Step	Language	Word	Meaning
1	Classical Persian	بنگالی	—
2	Arabic	بنغالي	Bengali
3	Arabic	ـِيّ	{{n-g\|suffix used to derive adjectives and...