Definition of: black hole

1. A dark cell or dungeon.
2. A military lock-up: in allusion to the Black Hole in Fort William, at Calcutta, a room 18 feet square, into which 146 British subjects were forced on the night of June 20, 1756, of whom 123 died of asphyxia before morning.
3. A hypothetical hole in space into which stars and other celestial objects that have condensed to a certain radius collapse under the influence of gravity.