All right for artist to have vegetable (4)
I believe the answer is:
okra
'vegetable' is the definition.
(okra is a kind of vegetable)
'all right for artist' is the wordplay.
'all right' becomes 'ok' (synonyms).
'for' is a charade indicator (letters next to each other).
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'ok'+'ra'='OKRA'
'to have' is the link.
(Other definitions for okra that I've seen before include "Ladies' fingers with edible pods" , "vegetable soup ingredient" , "Bhindi in Ind. cookery" , "Green pods, in stews" , "Lady's fingers; gumbo; bhindi" .)