Breadcrumb Home > Thesaurus > P Synonyms of pentagon Find synonyms for: Noun 1. Pentagon usage: a government building with five sides that serves as the headquarters of the United States Department of Defense 2. Pentagon, bureaucracy, bureaucratism usage: the United States military establishment 3. pentagon, polygon, polygonal shape usage: a five-sided polygon WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of pentagon (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: antebellum Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language