[ ˌʌɪkɒsə'hi:drən , -'hɛd- ]
■ noun ( plural icosahedra or ~s ) a three-dimensional shape having twenty plane faces, in particular a regular solid figure with twelve equal triangular faces.
Derivatives
icosahedral adjective
Origin
C16: via late L. from Gk eikosaedron , neut. (used asnoun) of eikosaedros 'twenty-faced'.