Not entirely uplifting process, it amuses artist (7)
I believe the answer is:
matisse
'artist' is the definition.
(Henri Matisse, 1869-1954, French artist)
'not entirely uplifting process it amuses' is the wordplay.
'uplifting' says the letters should be written backwards.
'not entirely' indicates a hidden word.
'essitam' can be found hidden inside 'process it amuses'.
'essitam' backwards is 'MATISSE'.
(Other definitions for matisse that I've seen before include "Mae sits badly for the French painter" , "Leading fauvist painter, d. 1954" , "Henri -, nineteenth-twentieth century French painter/sculptor" , "Henri ---, Fauvist painter" , "French painter, Henri, d.1954" .)