The painter possesses about a pound (4)
I believe the answer is:
hals
'the painter' is the definition.
(thesaurus)
'possesses about a pound' is the wordplay.
'possesses' becomes 'has' ('have' can be a synonym of 'possess').
'about' indicates putting letters inside.
'a pound' becomes 'l' (the pound sign is based on an L).
'has' placed around 'l' is 'HALS'.
(Other definitions for hals that I've seen before include "Frans - , Dutch painter (The Laughing Cavalier)" , "Frans --, Dutch artist" , "Sixteenth to seventeenth century Dutch artist known for portraits" , "Painter of The Laughing Cavalier, d. 1666" , "portrait painter" .)