1. A dilatory tactic, esp. prolonged and often irrelevant speechmaking, employed in an attempt to obstruct legislative action. • The filibuster is common in the U.S. Senate, where the right to debate is usu. unlimited and where a filibuster can be terminated only by a cloture vote of two-thirds of all members.
2. In a deliberative body, a member in the minority who resorts to obstructive tactics to prevent the adoption of a measure or procedure that is favored by the majority. — Also termed filibusterer.
3. Hist. A person who, together with others, works to invade and revolutionize a foreign state in disregard of international law. See CLOTURE. — filibuster, vb.