icosahedron(redirected from icosahedra)
Also found in: Dictionary, Thesaurus, Encyclopedia.
Related to icosahedra: Icosahedral symmetry
icosahedron(ī-kō″să-hē′drŏn, kŏs″) [Gr. eikosaedron]
A nearly spherical structure made of 20 identical subunits linked at 12 symmetrical corners. Each subunit is an equilateral triangle. Several viruses, including the human immunodeficiency virus (HIV), are icosahedral.