Biblical twin of Jacob (4)
I believe the answer is:
esau
'biblical twin of jacob' 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 man who sold his birthright for a mess of pottage" , "Biblical character who sold birthright for pottage" , "Cunning hunter" , "Hairy brother to Jacob in Bible" .)