The statutory limit that the United States Congress places on the
amount of debt that the Bureau of the Public Debt
can have outstanding at any time. Every few years (and sometimes
more than once in a single year), when the debt is
about to hit the limit, the Congress raises the limit, with a few
members taking the opportunity to say that "we should really do
something about the debt".
It used to be the case that Congress would designate an increase
in the debt ceiling as permanent or
temporary.
(There were also extensions, which didn't increase
the ceiling, but pushed back the expiration date for a temporary increase.)
Temporary ceiling increases can be considered in the same vein as
a temporary tax increase, namely, as a fairy tale.
In 1971, the
permanent debt ceiling was $400 billion. At the end of 1982, after
19 temporary increases, the permanent limit was still $400
billion dollars, while the debt was $1.197 trillion. Even politicians
were starting to see that they couldn't explain that forever, and would
have to fix that somehow -- so they discontinued the
temporary/permanent distinction.
As of January 31, 2002, the debt ceiling was 5,865,892,000,000 dollars.
As of this writing, it has been raised, but I don't have the current figure.
(The debt at February 28, 2002 was 6,003,453,016,583 dollars.)