Enneagon

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Enneagon \En"ne*a*gon\ (?; 277), n. [Gr. 'enne`a nine + gwni`a
     corner, angle: cf. enn['e]agone.] (Geom.)
     A polygon or plane figure with nine sides and nine angles; a
     nonagon.
     [1913 Webster]