Noun | 1. | ONI - the military intelligence agency that provides for the intelligence and counterintelligence and investigative and security requirements of the United States Navy United States Navy, US Navy, USN, Navy - the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces bureau, federal agency, government agency, agency, office, authority - an administrative unit of government; "the Central Intelligence Agency"; "the Census Bureau"; "Office of Management and Budget"; "Tennessee Valley Authority" IC, Intelligence Community, National Intelligence Community, United States Intelligence Community - a group of government agencies and organizations that carry out intelligence activities for the United States government; headed by the Director of Central Intelligence |