Definition on Senate website - Legislation in the form of a joint resolution enacted by Congress, when the new fiscal year is about to begin or has begun, to provide budget authority for Federal agencies and programs to continue in operation until the regular appropriations acts are enacted.
Senator Jim DeMint has proposed legislation (S.2070 - http://thomas.loc.gov/cgi-bin/query/z?c110:S.2070:) the “Government Shutdown Prevention Act” bill, which if passed would put a CR in place automatically so long as individual appropriations bills remain outstanding. Roll Call comments "That could lift some of the pressure on Members to pass massive omnibus bills that have received little scrutiny."