launcher UK /ˈlɔːntʃ.ə/US /ˈlɑnt͡ʃ.ɚ/ noun2 •One who or that which launches. A device that throws something or the person who initiates a launch.The catapult made a good launcher for the small projectile.They shot down the helicopter with a rocket launcher. •An application that launches another or others, often holding icons or menus for frequently used programs. formslaunchers