icosahedron

English

A regular icosahedron

Alternative forms

• eicosaedrum (obsolete)
• icosaedrum (obsolete)

Etymology

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

Pronunciation

• IPA^(key): /ˌaɪkoʊsəˈhiːdɹən/, /ˌaɪkɒsəˈhiːdɹən/, /ˌaɪkɔsəˈhiːdɹən/

• Audio (General American):

  (file)

Noun

icosahedron (plural icosahedra or icosahedrons)

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

   Synonym: regular gyroelongated pentagonal bipyramid

Derived terms

• great icosahedron
• hemi-icosahedron
• truncated icosahedron

Related terms

• icosahedral
• icosahedrite

Translations

a polyhedron

• Catalan: icosaedre (ca) m, icosàedre (ca) m
• Czech: dvacetistěn m, ikosaedr m
• Danish: ikosaeder n
• Dutch: regelmatig twintigvlak n, icosaëder (nl) m
• Esperanto: dudekedro
• Estonian: ikosaeeder (et), kakskümmendtahukas (et)
• Finnish: ikosaedri (fi)
• French: icosaèdre (fr) m
• German: Ikosaeder (de) m or n, Zwanzigflächner m
• Hungarian: ikozaéder (hu)
• Icelandic: tuttuguflötungur m
• Ido: ikosaedro (io)
• Japanese: 二十面体 (にじゅうめんたい, nijūmentai)
• Korean: 이십면체 (isimmyeonche)
• Norwegian:

  Bokmål: ikosaeder n

• Polish: dwudziestościan foremny m
• Portuguese: icosaedro (pt) m
• Russian: икоса́эдр (ru) m (ikosáedr), двадцатигра́нник (ru) m (dvadcatigránnik)
• Spanish: icosaedro (es) m
• Swedish: ikosaeder (sv) c
• Vietnamese: nhị thập diện

regular icosahedron

• Japanese: 正二十面体 (せいにじゅうめんたい, seinijūmentai)
• Korean: 정이십면체 (jeong'isimmyeonche)