The Rump Parliament was what remained of the Long Parliament after Pride's Purge on 6 December 1648, when Colonel Thomas Pride commanded his soldiers to exclude from the House of Commons those members who were against the Grandees' intention to try King Charles I for high treason. The Rump was dissolved by Oliver Cromwell in 1653 and replaced by the Barebone's Parliament. After Richard Cromwell's removal from power in 1659, the Rump was briefly reinstated.
"Rump" normally means the hind end or backside of a mammal; its use meaning "remnant" (the reduced-membership Parliament) was first recorded in the above context in English in 1649.