Definition of: filament

(fil′ə·mənt) noun
1. A fine thread, fiber, or fibril.
2. Any threadlike structure or appendage.
3. Bot. The stalk or support of an anther.
4. Electr. The slender wire of tungsten, carbon, or other material, which, when an electric current is passed through it in a vacuum, is heated to a brilliant glow and produces light. See illustration under INCANDESCENT LAMP.
5. Electronics A similar wire, forming the cathode of a vacuum tube, from which electrons are emitted under the action of heat.
6. Ornithol. The barb of a feather. [<F <LL filamentum <filare spin <filum a thread]