mp 18 Share definition Flag A German Made Sub-machine gun made in 1918 as a last ditch effort to help win in the last stages of World War 1 The MP 18 became a standard issue gun for some German troops in World War 1. mp 18 by SirXboxGamer May 7, 2018 0 0 Get merch Get the mp 18 mug. Buy Now — $32.95 See more merch