icosahedron

American  

[ahy-koh-suh-hee-druhn, ahy-kos-uh-] / aɪˌkoʊ səˈhi drən, aɪˌkɒs ə- /

noun

plural

icosahedrons, icosahedra

1. a solid figure having 20 faces.

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icosahedron British  

/ ˌaɪkəsəˈhiːdrən /

noun

1. a solid figure having 20 faces. The faces of a regular icosahedron are equilateral triangles

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icosahedron Scientific  

/ ī-kō′sə-hē′drən /

plural

icosahedrons

1. A polyhedron having twenty faces.

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Other Word Forms

• icosahedral adjective

Etymology

Origin of icosahedron

1560–70; < Greek eikosáedron, equivalent to eikosa- (variant of eikosi-, combining form of eíkosi twenty) + -edron -hedron

Example Sentences

Continental Drift is Earth in miniature, mapped onto a truncated icosahedron — a soccer ball — with its regular patchwork of 12 pentagonal faces and 20 hexagonal faces.

From New York Times • Jan. 1, 2023

There, he can sit and admire it along with the rest of a collection that includes work from real artists, such as the 80-inch infinity light icosahedron sculpture by L.A.’s Anthony James.

From Seattle Times • Dec. 5, 2022

All boron-boron bonds within each icosahedron are identical and are approximately 176 pm in length.

From Textbooks • Feb. 14, 2019

The maximum number of molecules that can be evenly assembled on the surface of an icosahedron is 60, but the number found in viruses is always much larger.

From Nature • Dec. 11, 2018

Thus we have a regular sequence of the platonic solids, and the question suggests itself, will further evolution develop elements shaped to the dodecahedron and the icosahedron?

From Occult Chemistry Clairvoyant Observations on the Chemical Elements by Sinnett, A. P.