Supreme god of ancient Greece (4)
I believe the answer is:
zeus
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">supreme god of ancient greece</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for zeus that I've seen before include "Chief among Greek gods" , "Supreme god of Greek myth" , "Greatest ancient Greek god" , "Chief Greek god" , "Supreme god of Ancient Greece" .)