"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").
polyglot
polygon
polygraph
polygyny
polyhedral
polyhedron
polyhistor
polymath
polymer
polymerase
polymeric