Cry 'Oh!' out loud when shut out (5)
I believe the answer is:
shout
'cry' is the definition.
(I know that cry can be written as shout)
'oh out loud when shut out' is the wordplay.
I cannot really see how this works, but
'oh' could be 'o' and 'o' is found in the answer.
The remaining letters 'shut' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for shout that I've seen before include "bellow" , "Utter a loud cry" , "Call loudly" , "Loud call" , "Noise" .)