Number of spectators watching an opener? (4)
I believe the answer is:
gate
'number of spectators' is the definition.
(gate can mean spectators at a sporting event)
'watching an opener?' is the wordplay.
I cannot really see how this works, but
'watching' could be 'at' (e.g. watching a tennis match means you are at it) and 'at' is found in the answer.
The remaining letters 'ge' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for gate that I've seen before include "Movable opening" , "Box office take" , "Entrance; street" , "Portal" , "Opening in a wall or fence" .)