Key part of gun (7)
I believe the answer is:
trigger
(Other definitions for trigger that I've seen before include "Pull it to discharge gun" , "trip" , "Start" , "Cause (device) to operate" , "One pulled to fire" .)
I believe the answer is:
trigger
(Other definitions for trigger that I've seen before include "Pull it to discharge gun" , "trip" , "Start" , "Cause (device) to operate" , "One pulled to fire" .)