From Longman Dictionary of Contemporary Englishblack holeˌblack ˈhole noun [countable] 1 HAHPan area in outer space into which everything near it, including light, is pulled2 informalBFMONEY something that uses up a lot of money I’m worried that the project could become a financial black hole.
Examples from the Corpus
black hole• The downtown area is an economic black hole.From Longman Business Dictionaryblack holeˌblack ˈhole noun [countable]COMMERCE a business activity or product on which large amounts of money are spent, but that does not produce any income or other useful resultAnyone who launches a bid for the company will want to be sure there are no more black holes lurking in its books. 