HEPTAHEDRON Meaning of HEPTAHEDRON in English [ ˌhɛptə'hi:drən , -'hɛd- ]■ noun ( plural heptahedra or ~s ) a solid figure with seven plane faces.Derivativesheptahedral adjective Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004