Birthright seller (4)
I believe the answer is:
esau
'birthright seller' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for esau that I've seen before include "He traded his birthright for a mess of pottage" , "Biblical character sounds as if he had a vision" , "Cunning hunter" , "Old Testament twin" , "Twin brother of Jacob" .)