1. a solid figure bounded by plane polygons or faces;
The Collaborative International Dictionary of English v.0.48:
Polyhedron \Pol`y*he"dron\, n.; pl. E. Polyhedrons., L.
Polyhedra. [NL., fr. Gr. ? with many seats or sides; poly`s
many + ? a seat or side: cf. F. poly[`e]dre.]
1. (Geom.) A body or solid contained by many sides or planes.
2. (Opt.) A polyscope, or multiplying glass.
WordNet (r) 3.0 (2006):
n 1: a solid figure bounded by plane polygons or faces