Said Python is a graven image (4)
I believe the answer is:
idol
'a graven image' is the definition.
(synonyms)
'said python' is the wordplay.
'said' indicates a 'sounds like' (homophone) clue.
'python' becomes 'idle' (Eric Idle, member of Monty Python).
'idle' sounds like 'IDOL'.
'is' acts as a link.
(Other definitions for idol that I've seen before include "loved one" , "Worshipped figure (not painting); revered person" , "Hero of screen or stage" , "Object of excessive love or devotion" , "A graven image or object of adoration" .)