pentahedronPronunciation: /ˌpɛntəˈhiːdr(ə)n, -ˈhɛd-/Definition of pentahedron noun (plural pentahedra /-drə/ or pentahedrons) a solid figure with five plane faces. Derivatives pentahedral adjective Origin: late 18th century: from penta- 'five' + -hedron, on the pattern of words such as polyhedronpentahedron in other Oxford dictionaries Definition of pentahedron in the US English dictionary
