Webster’s Revised Unabridged Dictionary · 1913
Decahedron
Dec′a·he′dron (·drŏn), n.; pl. E. Decahedrons (#), L. Decahedra (#). [Pref. deca- + Gr. ἔδρα a seat, a base, fr. ἔζεστηαι to sit: cf. F. décaèdre.] (Geom.) A solid figure or body inclosed by ten plane surfaces. [Written also, less correctly, decaedron.]