Celebrity extremely short with retired painter (4)
I believe the answer is:
star
'celebrity' is the definition.
(I've seen this before)
'extremely short with retired painter' is the wordplay.
'extremely' means to remove the middle letters (only the extremes of the word are used).
'with' means one lot of letters go next to another.
'retired' says the letters should be written in reverse.
'painter' becomes 'RA' (member of the Royal Academy of Arts).
'short' with its middle taken out is 'st'.
'ra' reversed gives 'ar'.
'st'+'ar'='STAR'
(Other definitions for star that I've seen before include "Red Dwarf?" , "Brilliant person" , "Celebrity - heavenly body" , "Arts (anag)" , "Actor in a principal role" .)