Players or cast, playing (6)
I believe the answer is:
actors
'players' is the definition.
('actor' can be a synonym of 'player')
'or cast playing' is the wordplay.
'playing' indicates an anagram.
'or'+'cast'='orcast'
'orcast' with letters rearranged gives 'ACTORS'.
(Other definitions for actors that I've seen before include "Luvvies" , "eg 9 & 11 across" , "Theatrical performers" , "They 23 down" , "Thespians" .)