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icosahedron Syllabification: i·co·sa·he·dron
Pronunciation: /īˌkōsəˈhēdrən/ /īˌkäsə-/

Definition of icosahedron in English:

noun (plural icosahedrons or icosahedra-drə)

A solid figure with twenty plane faces, especially equilateral triangular ones.
Example sentences
  • Four more Archimedeans appear in the Short book on the five regular solids: the truncated cube, the truncated octahedron, the truncated icosahedron and the truncated dodecahedron.
  • One of Plato's perfect solids, the icosahedron has 20 triangular faces.
  • Hypsicles relates that his father and Basilides studied a treatise by Apollonius on a dodecahedron and an icosahedron in the same sphere and decided that Apollonius's treatment was not satisfactory.


Late 16th century: via late Latin from Greek eikosaedron, neuter (used as a noun) of eikosaedros 'twenty-faced'.



Example sentences
  • You may note that the spheres sit more or less on the vertices of an icosahedron, which is why this configuration is called the icosahedral arrangement.
  • Thus, the combination of a spherical quadratic boundary potential and icosahedral rotational symmetry conditions maintained the initial distribution of solvation waters at the exterior boundary.
  • In order to simulate a calcium ion located on a symmetry axis under icosahedral boundary conditions, it was necessary to develop a single-atom model that conforms to the symmetry requirements.

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