a small arm operated by a mechanism, able to deliver a rapid and continuous fire of bullets as long as the trigger is pressed.
ma•chine-gunPronunciation: (mu-shēn'gun"), [key]
—v.t., -gunned, -gun•ning.
to shoot at with a machine gun.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.