black hole
1. A theoretical object in space, the mass of which is so great and dense that nothing, not even light, can escape its gravitational pull. Black holes have always fascinated me. If even light can't escape them, who knows what they might really contain?
2. Any place, region, or thing in which something (items, people, etc.) are irretrievably lost. My desk is just a black hole of papers and things, and I can never find anything in it! Alzheimer's is a terrible disease, like a black hole in one's mind.
3. A prison cell or area of confinement, especially that which is in notoriously poor or hostile condition. Refers specifically to the so-called "Black Hole of Calcutta," a prison in West Bengal where, in 1756, 146 Europeans were said to have been imprisoned and all but 23 suffocated overnight. Sebastian was sentenced to 30 days of solitary confinement in a tiny black hole, where the only light came from the slot for his food.
black hole
1. A wretched prison cell or other place of confinement. For example, The punishment is solitary confinement, known as the black hole. This term acquired its meaning in 1756 with the event known as the Black Hole of Calcutta. On the night of June 20, the ruler of Bengal confined 146 Europeans in a prison space of only 14 by 18 feet. By morning all but 23 of them had suffocated to death. Although historians since have questioned the truth of the story, it survives in this usage.
2. A great void or abyss. For example, Running a single small newspaper ad to launch a major campaign is useless; it amounts to throwing our money into a black hole . This usage alludes to a region, so named by astronomers, whose gravitational field is so intense that no electromagnetic radiation can escape from it. [Late 1970s]