Gun  —n. 1 weapon consisting of a metal tube from which bullets or other missiles are propelled with great force, esp. By a contained explosion. 2 starting pistol. 3 device for discharging insecticide, grease etc., in the required direction. 4 member of a shooting-party. 5 us gunman. —v. (-nn-) 1 a (usu. Foll. By down) shoot (a person) with a gun. B shoot at with a gun. 2 go shooting. 3 (foll. By for) seek out determinedly to attack or rebuke.  go great guns colloq. Proceed vigorously or successfully. Stick to one's guns colloq. Maintain one's position under attack. [perhaps an abbreviation of the scandinavian woman's name gunnhildr, applied to cannon etc.]