/ Thesaurus / F Synonyms of federal bureau of investigation Find synonyms for: Noun1. Federal Bureau of Investigation, FBI, law enforcement agencyusage: a federal law enforcement agency that is the principal investigative arm of the Department of JusticeWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: dormant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language