Greek sea god (8)
I believe the answer is:
poseidon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">greek sea god</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Greek god of the sea)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for poseidon that I've seen before include "Greek god of the sea and earthquakes" , "deity" , "Sea Lord" , "being able to create waves?" , "underwater missile" .)