Characters in the arts centre (5)
I believe the answer is:
heart
'centre' is the definition.
(I know that centre can be written as heart)
'characters in the arts' is the wordplay.
'characters in' says the answer is hidden in the clue.
'HEART' is hidden in the letters of 'the arts'.
(Other definitions for heart that I've seen before include "See 22" , "Centre; core" , "Central part" , "Core, courage" , "Playing card - pity" .)