Culture19th centuryEurope/Americashigh confidence

The word 'filibuster' derives from a Dutch word meaning 'freebooter' or pirate.

Notes on verification

Multiple independent etymological references (Etymonline, Merriam-Webster, Wiktionary, NPR) agree on the Dutch 'vrijbuiter' origin, transmitted through French and Spanish before entering English. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.887 clusters=4 claim_tier=notable | framework convergence=partial on standard historical linguistic/etymological scholarship (OED and related etymological dictionaries) (upstreams: Oxford English Dictionary, Century Dictionary) — publishers independent, evidence may not be | kind=empirical eligibility=high]

Sources