pentagon
nounCA, US /ˈpɛn.təˌɡɑn/ · UK /ˈpɛn.tə.ɡən/
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.
1
Geometry, Mathematics, Sciences A polygon with five sides and five angles.
- 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:
2
Government, Military, Politics, War A fort with five bastions.
- Synonyms
- 5-gon, quinquangle
- Derived terms
- pentagonal, pentagonoid, pentagonous
- Related terms
- pentagram, quinquangle