Body revealed by some actors on-stage (5)
I believe the answer is:
torso
'body' is the definition.
(a person's middle)
'some actors on-stage' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'TORSO' is hidden in the letters of 'actors on stage'.
'revealed by' is the link.
(Other definitions for torso that I've seen before include "Trunk; headless, limbless body" , "Body, minus its head and limbs" , "part of body will be found" , "Roots (anag)" , "Roost (anag)" .)