noun, plural i·co·sa·he·drons, i·co·sa·he·dra [ahy-koh-suh-hee-druh, ahy-kos-uh-] /aɪˌkoʊ səˈhi drə, aɪˌkɒs ə-/.
Origin of icosahedron
Examples from the Web for icosahedron
That for the tetrahedron has 12 for its order, for the cube (or octahedron) 24, and for the icosahedron (or dodecahedron) 60.
The Icosahedron, having twenty equilateral triangles as faces.Bygone Beliefs|H. Stanley Redgrove
Two of these generate the cube and the octahedron; five of these generate the dodecahedron and the icosahedron.Occult Chemistry|Annie Besant and Charles W. Leadbeater
An icosahedron is a figure comprehended under twenty equal sides.The Mystery of Space|Robert T. Browne
Associated words: vicenary, vigesimal, vigesimation, icosahedron.Putnam's Word Book|Louis A. Flemming
British Dictionary definitions for icosahedron
noun plural -drons or -dra (-drə)
Word Origin for icosahedron
Word Origin and History for icosahedron
1560s, from Greek eikosahedron, neuter of eikosahedros, from eikosi "twenty" + -hedra "seat, base, chair, face of a geometric solid," from PIE root *sed- (1) "to sit" (see sedentary). Greek eikosi is from PIE *wikmti- "twenty," from *wi- "in half," hence "two" + (d)kmti-, from root *dekm- "ten" (see ten).