- 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.
- a deep, immeasurable space into which people or things vanish; an abyss: I use earphones every day, but hate digging around for them in my black hole of a purse.
- 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.
- any usually wretched place of imprisonment or confinement.
- an object in space so dense that its escape velocity exceeds the speed of light
- any place regarded as resembling a black hole in that items or information entering it cannot be retrieved
