First murderer (4)
I believe the answer is:
cain
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">first murderer</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 cain that I've seen before include "Abel's brother" , "First son" , "First murderer reported in the Bible" , "Eldest son of Adam, Eve" , "First person born in Bible" .)