A cap Congress sets on how much total debt the US government can incur through borrowing, currently $16.394 trillion. Created by law in 1917 and altered 91 times since 1940, most recently in August 2011. Also known as the debt ceiling.
Congress knows what it means by terms such as 'fiscal cliff' or 'Simpson-Bowles,' but to many outside the Beltway they may as well be speaking Greek. Here's a translation of Washington's shorthand for budgetary issues now before the country – with each entry explained in 50 words or less.