Impressionist painter (5)
I believe the answer is:
monet
'impressionist painter' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for monet that I've seen before include "Claude -, French artist" , "he painted Rouen Cathedral" , "Claude --, French impressionist painter" , "French landscape painter" , "'Water Lilies' 13ac" .)