From Longman Dictionary of Contemporary Englishmachine gunmaˈchine gun noun [countable] PMWa gun that fires a lot of bullets very quickly There came the sound of men shouting and a burst of machine gun fire.
Examples from the Corpus
machine gun• He put several grenades in the coat pocket, and a machine gun into a long pocket inside the coat.• This is about the rate of a standard teleprinter, or a Bren machine gun.• His ship got shot down from three thousand feet over the pass by a fifty-caliber machine gun.• Wounded men all round him tried to get up and retreat, but only brought eruptions of machine gun fire.• Either the machine gun had been wiped out or the enemy had gotten smart.machine-gunmaˈchine-gun verb (machine-gunned, machine-gunning) [transitive] to shoot at someone or something with a machine gun He was machine-gunned in an ambush.→ See Verb table 