noun: (astronomy, physics) An astrophysical object (a "star") powered by dark matter particle self-annihilation.
noun: (obsolete, astronomy, physics) The equivalent of a black hole under the auspices of Newtonian gravitation. A star so massive, that its gravitational pull sets escape velocity above the speed of light, making the star dark, as no light can escape.
noun: Used other than figuratively or idiomatically: see dark, star.