He doesn't show his true feelings (5)
I believe the answer is:
actor
'his true feelings' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he doesn't show' is the wordplay.
I cannot really see how this works, but
'show' could be 'act' (act can mean a show or facade) and 'act' is found within the answer.
The remaining letters 'or' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for actor that I've seen before include "Thespian, stage performer" , "Films/stage worker" , "Gielgud, say" , "Player - performer" , "one to take on roles" .)