Synonyms and related words :
aperture, automatic, blowgun, blowpipe, broaching, cavity, chasm, check, clearing, cleft, crack, disclosure, fenestra, firearm, fistula, flamethrower, fontanel, foramen, gap, gape, gulf, gun, handgun, heater, hiatus, hole, hollow, inlet, interval, lacuna, laying open, leak, musket, opening, opening up, orifice, outlet, passageway, peashooter, piece, pistol, pore, repeater, revolver, rifle, rod, sawed-off shotgun, shooting iron, shotgun, six-gun, six-shooter, slot, space, split, stoma, throwing open, uncorking, unstopping, yawn