electron gun(n = noun.artifact) - the electrode that is the source of electrons in a cathode-ray tube or electron microscope; consists of a cathode that emits a stream of electrons and the electrostatic or electromagnetic apparatus that focuses it;
is a kind of electrode
is a part of cathode-ray tube, crt, electron microscope

ack-ack gun, air gun, antiaircraft gun, assault gun, bb gun, big gun, bofors gun, bren gun, browning machine gun, burp gun, electron, electron accelerator, electron beam, electron emission, electron lens, electron microscope, electron microscopic, electron microscopy, electron multiplier, electron optics, electron orbit, electron paramagnetic resonance, electron radiation, electron shell, electron spin resonance, electron tube, electron volt, field gun, free electron, gas gun, gatling gun, grease gun, gun, gun barrel, gun carriage, gun case, gun chamber, gun control, gun deck, gun dog, gun down, gun emplacement, gun enclosure, gun for, gun for hire, gun moll, gun muzzle, gun rest, gun room, gun smoke, gun trigger, gun turret, harpoon gun, high-angle gun, hired gun, hotchkiss gun, hydropneumatic gun carriage, jump the gun, krupp gun, light machine gun, machine gun, maxim gun, minute gun, naval gun, paintball gun, quaker gun, riot gun, set gun, smoking gun, spray gun, spring gun, squirt gun, staple gun, sten gun, stun gun, submachine gun, thompson submachine gun, tommy gun, valence electron, vickers' gun, vickers-maxim automatic machine gun, vickers-maxim gun, water gun, whaling gun, whitworth gun, wire gun, wire-wound gun, zip gun