Greek god shown in maze, usually (4)
I believe the answer is:
zeus
'greek god' is the definition.
(Zeus is an example)
'in maze usually' is the wordplay.
'in' indicates a hidden word.
'ZEUS' is hidden in the letters of 'maze usually'.
'shown' acts as a link.
(Other definitions for zeus that I've seen before include "Top deity on Olympus" , "Greeks' supreme deity" , "Supreme Greek deity" , "Supreme god of Ancient Greece" , "Ancient Greece's top god" .)