1 of 2

noun (1)

pen·​ta·​gon ˈpen-tə-ˌgän How to pronounce pentagon (audio)
: a polygon of five angles and five sides


2 of 2

noun (2)

: the U.S. military leadership

Examples of pentagon in a Sentence

Noun (1) The general attended a meeting at the Pentagon. There was disagreement between the President and the Pentagon over the new military budget.
Recent Examples on the Web
Regular pentagons cannot tile the plane, so fivefold symmetries are a natural place to look for tilings that can’t be periodic. Erica Klarreich, Quanta Magazine, 4 Apr. 2023 Penrose’s tilings, for instance, have fivefold symmetries, like those found in pentagons and five-pointed stars. Erica Klarreich, Quanta Magazine, 4 Apr. 2023 One of my favorites is an untitled work that features a plushy five-point star in shades of light brown enclosed in a red pentagon that fades to pink. Roberta Smith, New York Times, 2 Apr. 2020 If this pentagon were any bigger, five-star generals would show up for work at it. Ezra Dyer, Car and Driver, 30 Mar. 2020 The effect is a messy storyline that feels engineered to keep season 15’s stale-back-then love pentagon going. Ariana Romero,, 31 Jan. 2020 The pentagon is turning to crowdsourcing to come with some ideas. Kyle Mizokami, Popular Mechanics, 9 Feb. 2020 Preceding Orion are the bright autumn constellations Taurus the Bull, with the wonderful Pleiades star cluster, and Auriga, the constellation that looks like a lopsided pentagon with the bright star Capella. Mike Lynch, Twin Cities, 1 Dec. 2019 At the crime scene Sunday night, yellow police tape formed a pentagon around the intersection of North Kimball and North Allen avenues. Alice Yin,, 23 Sep. 2019

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'pentagon.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Noun (1)

Greek pentagōnon, from neuter of pentagōnos pentagonal, from penta- + gōnia angle — more at -gon

Noun (2)

the Pentagon building, headquarters of the Department of Defense

First Known Use

Noun (1)

1570, in the meaning defined above

Noun (2)

1945, in the meaning defined above

Time Traveler
The first known use of pentagon was in 1570

Dictionary Entries Near pentagon

Cite this Entry

“Pentagon.” Dictionary, Merriam-Webster, Accessed 26 May. 2024.

Kids Definition


pen·​ta·​gon ˈpent-ə-ˌgän How to pronounce pentagon (audio)
: a polygon of five angles and five sides

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