Astron.a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.
1. Also called Black' Hole' of Cal•cut'ta. a small prison cell in Fort William, Calcutta, in which, in 1756, Indians are said to have imprisoned 146 Europeans, only 23 of whom were alive the following morning.
2. (l.c.) any usually wretched place of imprisonment or confinement.