Bullfighters do a smart turn (8)
I believe the answer is:
matadors
'bullfighters' is the definition.
('matador' can be a synonym of 'bullfighter')
'do a smart turn' is the wordplay.
'turn' is an anagram indicator.
'do'+'a'+'smart'='doasmart'
'doasmart' anagrammed gives 'MATADORS'.
(Other definitions for matadors that I've seen before include "The bullfighters who kill the bulls" , "Spanish sportsmen" , "They kill bulls for sport" , "Spanish bull-fighters" .)