E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Filibuster.
A piratical adventurer. The most notorious was William Walker, who was shot in 1855. (French, flibustier, a corruption of our “freebooter;” German, freibeuter; Spanish, filibustero; Dutch, vrijbueter.) (See BUCCANEER.)
