Actor’s fear (5,6)
I believe the answer is:
stage fright
'actor's fear' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for stage fright that I've seen before include "problem for players" , "Nerves in front of an audience" , "Nervousness in front of audience" , "Performer's fear" , "attack of nerves" .)