icosahedron

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/(ˌ)aɪˌkoʊsəˈhiːdɹən//(ˌ)aɪˌkɒsəˈhiːdɹən//(ˌ)aɪˌkɔsəˈhiːdɹən/

noun

A polyhedron with twenty faces.

Similar
regular gyroelongated pentagonal bipyramid
OriginAncient Greek εἰκοσάεδρον →
UncommonScrabble 17
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Meanings

nounicosahedron (plural icosahedra or icosahedrons)

plural icosahedra · plural icosahedrons · alternative obsolete eicosaedrum · alternative obsolete icosaedrum

  1. geometryA polyhedron with twenty faces.
  2. specificallygeometryA regular icosahedron: one of the Platonic solids, all of whose faces are regular (equilateral) triangles

    Synonyms: regular gyroelongated pentagonal bipyramid

Synonyms & antonyms

nounA regular icosahedron: one of the Platonic solids, all of whose faces are regular (equilateral) triangles

Similar
regular gyroelongated pentagonal bipyramid

Origin

  1. Ancient Greekεἰκοσάεδρον
  2. Englishicosahedron

From Ancient Greek εἰκοσάεδρον (eikosáedron), from εἴκοσι (eíkosi, “twenty”) + ἕδρα (hédra, “face of a geometrical solid”). Equivalent to icosa- + -hedron.

More words from Ancient Greek

Full word history & related roots →

Translations

Ancient Greek εἰκοσάεδρον
  • εἰκοσάεδρον (eikosáedron)a polyhedron
Catalan icosaedre, icosàedre
  • icosaedrea polyhedron
  • icosàedrea polyhedron
Czech dvacetistěn, ikosaedr
  • dvacetistěna polyhedron
  • ikosaedra polyhedron
  • pravidelný dvacetistěnregular icosahedron
Danish ikosaeder
  • ikosaedera polyhedron
Dutch twintigvlak, icosaëder
  • twintigvlaka polyhedron
  • icosaëdera polyhedron
Esperanto dudekedro
  • dudekedroa polyhedron
Estonian ikosaeeder, kakskümmendtahukas
  • ikosaeedera polyhedron
  • kakskümmendtahukasa polyhedron
Finnish ikosaedri
  • ikosaedria polyhedron
French icosaèdre
  • icosaèdrea polyhedron
German Ikosaeder, Zwanzigflächner
  • Ikosaedera polyhedron
  • Zwanzigflächnera polyhedron
  • 20-Flächnera polyhedron
Greek εικοσάεδρο
  • εικοσάεδρο (eikosáedro)a polyhedron
Hungarian ikozaéder
  • ikozaédera polyhedron
Icelandic tuttuguflötungur
  • tuttuguflötungura polyhedron
Japanese 二十面体, 正二十面体
  • 二十面体 (nijūmentai)a polyhedron
  • 正二十面体 (seinijūmentai)regular icosahedron
Korean 이십면체, 정이십면체
  • 이십면체 (isimmyeonche)a polyhedron
  • 정이십면체 (jeong'isimmyeonche)regular icosahedron
Norwegian Bokmål ikosaeder
  • ikosaedera polyhedron
Polish dwudziestościan foremny
  • dwudziestościan foremnya polyhedron
Portuguese icosaedro
  • icosaedroa polyhedron
Russian икоса́эдр, двадцатигра́нник
  • икоса́эдр (ikosáedr)a polyhedron
  • двадцатигра́нник (dvadcatigránnik)a polyhedron
Spanish icosaedro
  • icosaedroa polyhedron
Swedish ikosaeder
  • ikosaedera polyhedron
Vietnamese nhị thập diện
  • nhị thập diệna polyhedron
Cite this entry
APA

icosahedron. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/icosahedron

MLA

“icosahedron.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/icosahedron. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “icosahedron,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/icosahedron.

Source: icosahedron on Wiktionary, CC BY-SA 4.0.