"having many faces" (as a solid body); "of or pertaining to a polyhedron," 1741, from polyhedron + -al (1). Related: Polyhedric; polyhedrical; polyhedrous.
Entries linking to polyhedral
polyhedron n.
"a solid bounded by many (usually more than 6) plane faces," 1560s, from Latinized form of Greek polyedron, neuter of adjective polyedros "having many bases or sides," from polys "many" (from PIE root *pele- (1) "to fill") + hedra "seat, base, chair, face of a geometric solid" (from PIE root *sed- (1) "to sit").
-al 1
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).