Jacob's sibling (4)
I believe the answer is:
esau
'jacob's sibling' 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 "Hairy OT man" , "Hairy brother to Jacob in Bible" , "Jacob's brother in the bible" , "brother done in Bible" , "Rebecca's son" .)