The term "budget deficit" refers to the current fiscal policy employed by the US Congress, presidential administration and Federal Reserve (Also known as the presidents credit card debt). It means "spending more money than we take in". Keynesian economists argue that running this type of fiscal policy short-term stimulates the economy, as an antidote to the malady known as recessionitis. Additionally, it has been found to also stimulate inflation (sometimes), debt, and really big negative numbers which look scary because they're red rather than green or black.