Is 'pentagon' always capitalized?

No. Lowercase 'pentagon' refers to the geometric shape. Capitalized 'The Pentagon' refers specifically to the headquarters of the US Department of Defense.

Can 'pentagon' be used as a verb?

No, 'pentagon' is exclusively a noun. The related adjective is 'pentagonal'.

What is the difference between a 'pentagon' and a 'pentagram'?

A pentagon is a five-sided polygon. A pentagram is a star-shaped figure formed by drawing the five diagonals of a regular pentagon, often associated with symbolism.

Why is the US Defense building called the Pentagon?

It is named for its distinctive five-sided architectural shape, chosen to fit the building site efficiently.

Is “pentagon” formal?

Pentagon is usually formal (geometric), formal/news (building) in register.

How do you pronounce “pentagon”?

Pentagon: in British English it is pronounced /ˈpen.tə.ɡən/, and in American English it is pronounced /ˈpen.t̬ə.ɡɑːn/. Tap the audio buttons above to hear it.

pentagon: meaning, definition, pronunciation and examples

UK/ˈpen.tə.ɡən/US/ˈpen.t̬ə.ɡɑːn/

Formal (geometric), Formal/News (building)

My Flashcards

Quick answer

What does “pentagon” mean?

A two-dimensional geometric shape with five straight sides and five angles.

Audio

Pronunciation

Definition

Meaning and Definition

A two-dimensional geometric shape with five straight sides and five angles.

Often refers specifically to the headquarters of the United States Department of Defense, a building shaped like a pentagon.

Dialectal Variation

British vs American Usage

Differences

No significant difference in meaning. The geometric term is universal. The reference to the US military headquarters is understood globally but is more frequent in American media.

Connotations

In British English, 'pentagon' is primarily geometric; references to 'The Pentagon' are understood as a metonym for US defense policy. In American English, 'The Pentagon' is a common synecdoche for the US military establishment.

Frequency

The geometric term has similar frequency. The proper noun 'The Pentagon' is vastly more frequent in American English due to domestic news coverage.

Grammar

How to Use “pentagon” in a Sentence

[verb] a pentagona pentagon [verb][adjective] pentagonpentagon of [noun]

Vocabulary

Collocations

strong

regular pentagonThe PentagonPentagon officialsPentagon spokesmanirregular pentagon

medium

shape of a pentagonPentagon budgetPentagon reportdraw a pentagonfive-sided pentagon

weak

large pentagonnew Pentagoncalled a pentagonlike a pentagonperfect pentagon

Examples

Examples of “pentagon” in a Sentence

adjective

British English

The pentagonal shape was clearly visible.
They studied pentagonal numbers.

American English

The pentagonal layout of the plaza is unique.
He explained the pentagonal symmetry.

Usage

Meaning in Context

Business

Rare, except in contexts related to defense contracting (e.g., 'a Pentagon contract').

Academic

Common in geometry and mathematics; also in political science/international relations when discussing US foreign policy.

Everyday

Primarily the geometric shape. References to 'The Pentagon' occur in news consumption.

Technical

Precise geometric term; in defense/security discourse, refers to the institution and its decisions.

Vocabulary

Synonyms of “pentagon”

Strong

The Pentagon (for the building)US Defense Department (for the institution)

Neutral

five-sided figure5-gon

Weak

five-sided shapegeometric figure

Vocabulary

Antonyms of “pentagon”

circle triangle square

Watch out

Common Mistakes When Using “pentagon”

Misspelling as 'pentagon' (lowercase) when referring specifically to the US military headquarters, which requires capitalization ('The Pentagon').
Using 'pentagon' as a general term for any government military building.

FAQ

Frequently Asked Questions

: No. Lowercase 'pentagon' refers to the geometric shape. Capitalized 'The Pentagon' refers specifically to the headquarters of the US Department of Defense.
: No, 'pentagon' is exclusively a noun. The related adjective is 'pentagonal'.
: A pentagon is a five-sided polygon. A pentagram is a star-shaped figure formed by drawing the five diagonals of a regular pentagon, often associated with symbolism.
: It is named for its distinctive five-sided architectural shape, chosen to fit the building site efficiently.
: A two-dimensional geometric shape with five straight sides and five angles.
: Pentagon is usually formal (geometric), formal/news (building) in register.
: Pentagon: in British English it is pronounced /ˈpen.tə.ɡən/, and in American English it is pronounced /ˈpen.t̬ə.ɡɑːn/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

“The Pentagon's walls have ears.”

Learning

Memory Aids

Mnemonic

PENTAgon has PENTA (like 'pentathlon' for five events) + GON (like 'polygon' for shape). Think: a five-angled shape.

Conceptual Metaphor

THE PENTAGON IS THE US MILITARY ESTABLISHMENT (Metonymy/Synecdoche).

Practice

Quiz

Fill in the gap

For her geometry test, she had to calculate the area of a regular .

Multiple Choice

What does 'The Pentagon' most specifically refer to in international news?