An Etymological Dictionary of Astronomy and Astrophysics

A very large-scale structure made of → galaxy clusters threaded like beads on a chain. Cosmic filaments are chiefly made up of → dark matter
but also, to a lesser extent, of → baryonic matter. They are the largest entities in the → Universe and can be up to 1 billion → light-years long. They are separated by great → voids.

See also: → cosmic; → filament.