Wiktionary
quadruple star
n. 1 (context star English) Four stars which form a stellar system, such that they orbit the point of equilibrium of their gravitational fields; a quadruple star system. 2 (context star English) Four stars that appear to be one when seen with the naked eye, either because they orbit one another (quadruple star systems) or happen to be in the same line of sight even though they are separated by a great distance.