River flowing into the Bay of Bengal (6)
I believe the answer is:
ganges
'river flowing into the bay of bengal' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ganges that I've seen before include "Sacred river of N India" , "Indian flower" , "Sacred Indian river" , "Holy river on India" , "River flowing into the Bay of Bengal" .)