Jacob's biblical brother (4)
I believe the answer is:
esau
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">jacob's biblical brother</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for esau that I've seen before include "Jacob's brother (OT)" , "Isaac's eldest son" , "Jacob's twin (Bible)" , "Isaac's hairy son" , "Biblical character who sold birthright for pottage" .)