Image of false god held by wicked one (7)
I believe the answer is:
eidolon
'image' is the definition.
(an eidolon is an image or ideal)
'false god held by wicked one' is the wordplay.
'false god' becomes 'idol' (I've seen this before).
'held by' is an insertion indicator.
'wicked' indicates anagramming the letters.
'one' anagrammed gives 'eon'.
'idol' placed into 'eon' is 'EIDOLON'.
'of' acts as a link.
(Other definitions for eidolon that I've seen before include "ideal thing" , "Spectre, phantom; no oldie (anag.)" , "Reflected image" .)