Meaning of “gun” - Learner’s Dictionary

gun

noun [ C ] us uk /ɡʌn/
They held a gun to his head.He fired his gun into the air.I heard a gun shot and decided to call the police.He pulled a gun on us and demanded money.He has always been in favour of stricter gun controls.

B1 a weapon that you fire bullets out of

(Definition of “gun” from the Cambridge Learner’s Dictionary © Cambridge University Press)