pentakaidecahedronEtymologyFrom Ancient Greek πέντε (pénte, “five”) + καί (kaí, “and”) + δέκᾰ (dékă, “ten”) + -hedron.pentakaidecahedron means synonym of pentadecahedron. Lexicurio rates it Rare gem — a strength score of 82 out of 100.nounSynonym of pentadecahedron.“The lacunar pattern of this grain therefore includes six tetragonal and nine hexagonal faces. Relating this to polyhedrons, we find that no pentakaidecahedron with such a combination of faces can exist (see page 199).”