filibuster , n : A mercenary soldier; a freebooter; specifically, a mercenary who travelled illegally in an organized group from the United States to a country in Central America or the Spanish West Indies in the mid-19th century seeking economic and political benefits through armed force. (politics, US) A tactic (such as giving long, often irrelevant speeches) employed to delay the proceedings of, or the making of a decision by, a legislative body, particularly the United States Senate. (politics, US) A member of a legislative body causing such an obstruction; a filibusterer. One of the first filibusters in the United States Senate, involving an attempt to prevent a censure of President Andrew Jackson from being expunged from the Senate record, began on this date in 1837.