H0155400 (hĕp′tə-gŏn′)n. A polygon with seven sides and seven angles.[Latin heptagōnon, from Greek heptagōnos, having seven angles : hepta-, hepta- + -gōnos, angled; see -gon.]hep·tag′o·nal(-tăg′ə-nəl) adj.TranslationsettagonaleEncyclopediaSeeheptagon