Where does “জলজ” come from?

জলজ (Bengali) comes from Bengali জল, from Sanskrit जल, from Sanskrit जल् — to be sharp; to be stiff or dull.

জলজ (Bengali): aquatic

Definitions

Step	Language	Word	Meaning
1	Bengali	জল	water
2	Sanskrit	जल	stupid, unintelligent, dumb; a stupid man, idiot;...
3	Sanskrit	जल्	to be sharp; to be stiff or dull

জলজ — Etymology, Origin & Word History | Etymology Explorer