Breadcrumb Home > Thesaurus > I Cite Synonyms of investigation Find synonyms for: Noun1. probe, investigation, inquiry, enquiry, researchusage: an inquiry into unfamiliar or questionable activities; "there was a congressional probe into the scandal"2. investigation, investigating, workusage: the work of inquiring into something thoroughly and systematicallyWordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.Definition and meaning of investigation (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. February 2021 Current Events: US News The Berlin Conference and the Partition of Africa The Implied Powers of Congress Noble Titles and Ranks in a Monarchy Keeping Your Brain Active in a COVID-19 World The Manchu Related Content Daily Word Quiz: puerile Analogy of the Day: Today?s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language