The supreme god of the ancient Greeks (4)
I believe the answer is:
zeus
'the supreme god of the ancient greeks' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for zeus that I've seen before include "Celestial ruler" , "Suez (anag)" , "His statue was one of Seven Wonders of the World" , "old Greek" , "Chief Olympian deity" .)