Noun
1. a weapon that discharges a missile at high velocity (especially from a metal tube or barrel)
2. large but transportable armament
3. a person who shoots a gun (as regards their ability)
4. a professional killer who uses a gun
5. a hand-operated pump that resembles a gun; forces grease into parts of a machine
6. a pedal that controls the throttle valve;
"he stepped on the gas"7. the discharge of a gun as signal or as a salute in military ceremonies;
"a twenty gun salute"