Definition of "dodecahedron" [do•dec•a•he•dron]

• A polyhedron with 12 faces. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "A dodecahedron is any polyhedron with twelve faces, but usually a regular dodecahedron is meant: a Platonic solid composed of twelve regular pentagonal faces, with three meeting at each vertex."
• "The hyperbolic dodecahedron is quite symmetric and has the same symmetry group as a regular dodecahedron."
• "To the ancient Greeks, the dodecahedron was a symbol of the Universe."