science an area in outer space where the force of gravity is so strong that light and everything else around it is pulled into it 黑洞（外层空间一区域，引力极大，能将光和周围的所有东西都吸入）
2
informal a situation in which large amounts of money are spent without bringing any benefits 无底洞
The business was little more than a financial black hole. 这个企业只是财政上的无底洞罢了。
3
informal a situation in which there is a lot of sadness and very little hope 悲伤绝望
the psychological black hole of long-term unemployment 长期失业造成的心理上的绝望