black hole noun definition in The universe topic from the Oxford Advanced Learner's Dictionary

black hole

 noun: The universe topic
an area in space that nothing, not even light, can escape from, because gravity (= the force that pulls objects in space towards each other) is so strong there (figurative) The company viewed the venture as a financial black hole (= it would use a lot of the company's money with no real result). (figurative) Thousands of people have been plunged into the black hole of unemployment.