pentagon

[ pen-tuh-gon, -guh n ]
/ ˈpɛn təˌgɒn, -gən /

noun

a polygon having five angles and five sides.
the Pentagon,
  1. a building in Arlington, Virginia, having a plan in the form of a regular pentagon, containing most U.S. Defense Department offices.
  2. the U.S. Department of Defense; the U.S. military establishment.

Origin of pentagon

1560–70; < Late Latin pentagōnum < Greek pentágōnon, noun use of neuter of pentágōnos five-angled. See penta-, -gon

Related forms

pen·tag·o·nal [pen-tag-uh-nl] /pɛnˈtæg ə nl/, adjectivepen·tag·o·nal·ly, adverbsub·pen·tag·o·nal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for pentagon

British Dictionary definitions for pentagon (1 of 2)

pentagon

/ (ˈpɛntəˌɡɒn) /

noun

a polygon having five sides

Derived Forms

pentagonal (pɛnˈtæɡənəl), adjective

British Dictionary definitions for pentagon (2 of 2)

Pentagon

/ (ˈpɛntəˌɡɒn) /

noun

the five-sided building in Arlington, Virginia, that houses the headquarters of the US Department of Defense
the military leadership of the US

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for pentagon

pentagon

[ pĕntə-gŏn′ ]

A polygon having five sides.

Related forms

pentagonal adjective (pĕn-tăgə-nəl)
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for pentagon (1 of 2)

Pentagon

An immense five-sided building in Virginia, just outside Washington, D.C., that serves as headquarters for the Department of Defense.


Note

The term is often used to refer to the Department of Defense or the military: “The Pentagon agreed today to submit the modified weapons plan to the president.”

Note

The Pentagon was severely damaged by the September 11 attacks.

Culture definitions for pentagon (2 of 2)

pentagon

A polygon having five sides.


Note

The Pentagon is a huge five-sided building near Washington, D.C., that contains offices of the Department of Defense.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.