Jacob's brother (4)
I believe the answer is:
esau
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">jacob's 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 "Would-be fratricide" , "brother done in Bible" , "scriptural character" , "Elder of the twin sons of Isaac and Rebecca" , "Isaac's hairy son" .)