Filament may refer to: In physics and electrical engineering An electrical filament used to emit light in an Incandescent light bulb Current filament Filament propagation, diffractionless propagation of a light beam Hot cathode, a filament in a vacuum tube that emits electrons In astronomy Galaxy filament Solar filament, a structure in a solar corona Birkeland current In biology Protein filament Filamentation, a long chain of cells Part of a stamen, the male part of a flower Hypha, in fungi a… (More on Filament)