Alright for painter to have a vegetable (4)
I believe the answer is:
okra
'a vegetable' is the definition.
(okra is a kind of vegetable)
'alright for painter' is the wordplay.
'alright' becomes 'OK' (synonyms).
'for' is a charade indicator (letters next to each other).
'painter' becomes 'RA' (member of the Royal Academy of Arts).
'ok'+'ra'='OKRA'
'to have' is the link.
(Other definitions for okra that I've seen before include "Lady's fingers; gumbo; bhindi" , "Green pods, in stews" , "Edible seed pods" , "Pod eaten in soups, stews etc" , "Long green tropical vegetable" .)