polyhedric, polyhedrical

[POLYHEDRON.] The same as POLYHEDRAL (q. v.). pol-y-he-dron, *pol-y-e-dron, subst. [Pref. poly-, and Gr. hedra a seat, a base.] 1. Geom.: A solid, bounded by polygons. The bounding polygons are called faces; the lines in which they meet are called edges, and the vertices of the polyhedral angles are called vertices of the polyhedron. A straight line joining two vertices, not in the same face, is called a diagonal, and a plane pa ing through three vertices, not in the same face, is called a diagonal plane. When the faces are regular polygons, the polyhedron is said to be regular; there are but five such polyhedrons, viz.: the regular tetrahedron, hexahedron, octahedron, dodecahedron, and icosahedron. 2. Optics : A poly scope (q. v.). pol-y-he-drous, a. [POLYHEDRAL.] †pol-y-his-tor, s . [Pref. poly- , and Gr. hist or = learned.] A person of great learning; one versed in many sciences. pol-ý-hy-dric, a. [Pref. poly-; Eng. hydr (oxyl), and suff. -ic.] (See compound.) polyhydric-alcohols, s. pl. Chem.: Alcohols containing more than one semi molecule of hydroxyl. pol-ý-hy-drīte, s. [Pref. poly-, and Gr. hydör =water; suff. -ite ( Min.).] Min.: An amorphous mineral, of a liver-brown color, of somewhat doubtful composition. Said to contain silica, pro to and sesquioxides of iron, with some alumina, ., and 29-20 per cent. of water. Found at Breitenbrunn, Saxony. Poly hymn i a Põl-y-hym-ni-a, s. [Lat., from Gr. Polymnia, from polys many, and hymnos =a hymn.] 1. Cla . Antiq.: One of the Muses, daughter of Jupiter and Mnemosyne, who presided over singing and rhetoric, and was deemed the inventre of harmony. She was variously represented; sometimes veiled in white, holding a scepter in her left hand, and with her right raised up, as if ready to harangue. 2. Astron .: [ASTEROID, 33.]