People run when he shoots (7)
I believe the answer is:
starter
'he shoots' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'people run' is the wordplay.
I cannot quite understand how this works, but
'run' could be 'r' (cricket abbreviation) and 'r' is present in the answer.
'people' could be 'state' (as in the people of a nation) and 'state' is located in the remaining letters.
A single letter 'r' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'when' acts as a link.
Can you help me to learn more?
(Other definitions for starter that I've seen before include "One giving signal to begin race" , "Type of home" , "Race gun firer" , "Appetiser" , "No substitute" .)