"Subprime" has been voted word of the year for 2007 by linguists of the American Dialect Society.
The US subprime crisis has led to thousands of foreclosures
Used to describe a risky loan, the word burst out of the banking sector as the home loan crisis in the US turned into a global credit squeeze.
It beat competition from Facebook, water-boarding and Googleganger.
The society says it just charts words or phrases that have become prominent in a particular year, and is not telling people how to speak.
"Subprime" means literally "less than ideal" and is the technical term used to describe loans - especially mortgages - made to borrowers with poor credit histories.
A series of defaults on such loans spread panic through much of the banking sector in 2007 as financial institutions realised they had bought many of these loans from one another without knowing how risky they were.
American Dialect Society spokesman Wayne Glowka said: "When you have investment companies losing billions of dollars over something like bundled subprime loans, then you have to consider whether it's important.
"You probably also want to think about paying off that third mortgage."
Other words nominated for the award included "water-boarding" - a form of interrogation involving simulated drowning, that was much discussed in recent confirmation hearings - and "Facebook", a popular social networking website.
The society gave its "most creative word" award to "Googleganger" - meaning a person thrown up by a Google search on your name, but who is not you.
Among other citations this year:
- Ninja - a poorly documented loan made to a high-risk borrower - someone with No Income, No Job or Assets
- Wrap rage - anger brought on by the inability to open a factory-sealed package
- Tapafication - the tendency of restaurants to serve food in many small portions, like tapas.