The Collaborative International Dictionary
go belly-up
belly up \bel"ly up`\, belly-up \bel"ly-up`\, a. [from analogy to the position of a floating dead fish.] defunct; bankrupt; -- used mostly of commercial organizations; often used in the phrase
go belly-up, i. e. to go bankrupt.
Wiktionary
go belly-up
vb. 1 (context idiomatic English) To die. 2 (context idiomatic English) To fail or fold; especially, to close or shut down a business; to go out of business.