Painter, for instance, in sad disarray (5)
I believe the answer is:
degas
'painter' is the definition.
(Edgar Degas, 1834-1917)
'for instance in sad disarray' is the wordplay.
'for instance' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'in' means one lot of letters goes inside another.
'disarray' indicates anagramming the letters.
'sad' with letters rearranged gives 'das'.
'eg' inserted inside 'das' is 'DEGAS'.
(Other definitions for degas that I've seen before include "Edgar ---, Fr. impressionist" , "Edgar ---, ballet-dancer painter" , "He produced works of art" , "Edgar --, French artist" , "French artist known for his ballet scenes, d.1917" .)