Painter foremost in British art study (5)
I believe the answer is:
bacon
'painter' is the definition.
(Francis Bacon)
'foremost in british art study' is the wordplay.
'foremost in' says to take the initial letters.
'study' becomes 'con' (I've seen this before**).
The initial letters of 'british art' is 'ba'.
'ba'+'con'='BACON'
(Other definitions for bacon that I've seen before include "Francis ---, Ir. painter" , "Bring this meat home to be a winner" , "Sizzling" , "Meat one can bring home" , "Cured meat from pig" .)