资料来源 : pyDict

九边形

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Nonagon \Non"a*gon\, n. [L. nonus ninth + Gr. ? angle.] (Math.)
   A figure or polygon having nine sides and nine angles.

资料来源 : WordNet®

nonagon
     n : a nine-sided polygon