Wiktionary
n. 1 (context idiomatic English) A possession or financial commitment that creates substantial ongoing expenses, especially one whose costs are considered to be unsustainable. 2 (context sometimes capitalized English) 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.
Wikipedia
Money Pit is a British television series on Dave as of 28 October 2015. It is presented by Jason Manford and Dominic Frisby.
Usage examples of "money pit".
These disastrous investments added to his losses in oil refining, the money pit of the Founders Inn Hotel, his jet leasing fiasco and one of England’.
Even by government agency standards, NASA was an astounding money pit&mdash.
Blackacre was a money pit, a bottomless well you threw money into.
It had been a bit of a money pit in the beginning and my Bank Manager had not looked favourably on a Pupil Barrister taking on such a pile of debt.
Ukraine had few outside enemies except for its tenuous relationship with its former parent, Russia, so the longrange supersonic Backfires had been considered nothing more than a useless, dangerous money pit.
The Money Pit had always been one of her favorites and she sat down on the edge of the bed and lost herself in the antics of Hanks and Shelley Long.