Douglas Harper's Etymology Dictionary
"light, portable machine gun," 1926, from sub- + machine gun.
Usage examples of "sub-machine gun".
Every single one of those men was armed, with the latest Merlin sub-machine gun loaned from-the Army, with specific instructions to shoot to kill if anyone batted an eyelid.
They had both worked together like the well-oiled parts of an HK MP-5 sub-machine gun ever since.
He ran a hand over the stubble on bis chin and leaned back in the seat watching the road, a sub-machine gun in his lap.
As soon as her shot started the game, Tovera's sub-machine gun would finish it.
Two of them were talking in low voices to Hogg, who ignored the SP on one side of him and the blocky civilian with a sub-machine gun on the other.
At the shot, a thug with a sub-machine gun sprayed a burst into the stone floor and his own feet.
There was a table, chairs, a rack holding numerous silver garments, opened cases of sub-machine gun ammunition, and other boxes holding rapid-firers and hand grenades.
Cunningham checked the action of his sub-machine gun and slipped it out of sight under his outer robe, holding it with one hand.