pentagon
UK /ˈpɛn.tə.ɡən/ · US /ˈpɛn.təˌɡɑn/ noun, proper noun
Forms pentagons the Pentagon
- noun (geometry) A polygon with five sides and five angles.
- noun (military) A fort with five bastions.
- proper noun The headquarters of the United States Department of Defense.
- proper noun (metonymic) The United States Department of Defense.
Synonyms
Etymology
From Middle French pentagone, from Late Latin pentagōnum, from Ancient Greek πεντάγωνον (pentágōnon), noun use of the neuter of the adjective πεντάγωνος (pentágōnos, “five-angled”), from πέντε (pénte, “five”) + -γωνος (-gōnos, “angled”). Equivalent to penta- + -gon.
From the shape of the building.
Webster’s 1913
- noun A plane figure having five angles, and, consequently, five sides; any figure having five angles. Regular pentagon, a pentagon in which the angles are all equal, and the sides all equal.
Etymology [Gr. Penta-) + gwni`a angle: cf. L. pentagonium, F. pentagone.]
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “pentagon”, CC BY-SA 4.0. Details