Jacob's twin (4)
I believe the answer is:
esau
'jacob's twin' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for esau that I've seen before include "wronged brother" , "scriptural character" , "Biblical character who sold birthright for pottage" , "He traded his birthright for a mess of pottage" , "brother done in Bible" .)