pentagon

Noun

pentagon (plural pentagons)

1. A polygon with five sides and five angles.
   • Meronyms: angle, side; see also Thesaurus:polygon
   • Imagine a vast sheet of paper on which straight Lines, Triangles, Squares, Pentagons, Hexagons, and other figures, instead of remaining fixed in their places, move freely about, […]1884, A Square [pseudonym; Edwin A. Abbott], Flatland […] , London: Seeley & Co., Part I: This World, § 1.— Of the Nature of Flatland, page 3

   Synonyms:

   5-gon, quinquangle

2. A fort with five bastions.

Proper noun capitalized: Pentagon

US/ˈpɛntəɡɑn/UK/ˈpɛntəɡən/

the Pentagon

1. The headquarters of the United States Department of Defense.
2. (metonymically) The United States Department of Defense.
   • The Vietnamese people inspired youth of all nationalities […] by demonstrating that the determination of a people to fight for their sovereignty and right to self-determination was an unconquerable force, even in the face of Pentagon might.2006 August 24, Leslie Feinberg, “Many histories converged at Stonewall”, in Workers World
   • Asked by CNN what measures DHS was taking after the Pentagon leaks, Mayorkas said the department issued a reminder to employees and that he had directed a review.2023 May 16, Priscilla Alvarez, “DHS directs review of personnel with access to classified material in wake of Pentagon leak”, in CNN

   Synonyms:

   Pentagram