Remove top of picture for sorcerer (4)
I believe the answer is:
mage
'sorcerer' is the definition.
(I've seen this before)
'remove top of picture' is the wordplay.
'remove top of' means to remove the first letter (I've seen 'removes top' mean this).
'picture' becomes 'image' (synonyms).
'image' with its initial letter taken away is 'MAGE'.
'for' is the link.
(Other definitions for mage that I've seen before include "Wise man" , "Learned person (arch.)" , "Sorcerer" .)