Post-Impressionist painter (7)
I believe the answer is:
cezanne
'post-impressionist painter' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for cezanne that I've seen before include "French artist" , "Paul --, French painter" , "Painter of the 'Card Players' series" , "French impressionist painter" , "Paul ---, post-Impressionist" .)