POLYHALITE
Pol`y*ha"lite, n. Etym: [Poly- + Gr. (Min.)

Defn: A mineral usually occurring in fibrous masses, of a brick-red color, being tinged with iron, and consisting chiefly of the sulphates of lime, magnesia, and soda.

POLYHEDRAL; POLYHEDRICAL
Pol`y*he"dral, Pol`y*hed"ric*al, a. Etym: [See Polyhedron.] (Geom.)

Defn: Having many sides, as a solid body. Polyhedral angle, an angle bounded by three or more plane angles having a common vertex.

POLYHEDRON
Pol`y*he"dron, n.; pl. E. Polyhedrons., L. Polyhedra. Etym: [NL., fr.
Gr. polyèdre.]

1. (Geom.)

Defn: A body or solid contained by many sides or planes.

2. (Opt.)

Defn: A polyscope, or multiplying glass.

POLYHEDROUS
Pol`y*he"drous, a.