i·co·sa·he·dron 
(ī-kō′sə-hēdrən, ī-kŏs′ə-)
(ī-kō′sə-hēdrən, ī-kŏs′ə-)n. pl. i·co·sa·he·drons or i·co·sa·he·dra (-drə)
A polyhedron having 20 faces.
[Greek eikosaedron, from neuter of Greek eikosaedros, twenty-sided : eikosi, twenty; see wīktī- in the Appendix of Indo-European roots + -edros, -sided; see -HEDRON.]
i·co′sa·hedral (-drəl) adj.
icosahedron