1. money pit - Noun
2. Money pit - Proper noun
money pit (plural money pits)
(idiomatic) A possession or financial commitment, especially a building or vehicle, that creates substantial ongoing expenses, especially one whose costs are considered to be unsustainable.
money pit
(sometimes capitalized) Long-standing nickname of a complicated, seemingly man-made excavation on Oak Island in Nova Scotia, Canada, rumored to contain pirate treasure and which has been repeatedly and unsuccessfully probed at great expense.
The team then turned their focus to Lot 15, an area not far from the fabled Money Pit. Source: Internet