Twitter Google Share on Facebook heptagon (redirected fromSeptagon) Thesaurus Encyclopedia Related to Septagon:polygon heptagon hep·ta·gon (hĕp′tə-gŏn′) n. A polygon with seven sides and seven angles. [Latinheptagōnon, from Greekheptagōnos,having seven angles:hepta-,hepta-+-gōnos,...