FILIBUSTER, a name originally given to the buccaneers (q.v.). The term is derived most probably from the Dutch vry buiter, Ger. Freibeuter, Eng. freebooter, the word changing first into fribustier, and then into Fr. flibustier, Span. filibustero. Flibustier has passed into the French language, and filibustero into the Spanish language, as a general name for a pirate. The term "filibuster" was revived in America to designate those adventurers who, after the termination of the war between Mexico and the United States, organized expeditions within the United States to take part in West Indian and Central American revolutions. From this has sprung the modern use of the word to imply one who engages in private, unauthorized and irregular warfare against any state. In the United States it is colloquially applied to legislators who practise obstruction.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)