Shape with one more side than a stop sign

• A regular one has internal angles of 140 degrees
• Odd-shaped figure
• Nine-sider
• Defective stop sign?
• Geometric figure
• It has nine angles and nine sides
• Figure a small number continue to badger
• Nine-sided polygon

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Nonagon \Non"a*gon\, n. [L. nonus ninth + Gr. ? angle.] (Math.) A plane figure or polygon having nine sides and nine angles.

WordNet Word definitions in WordNet
n. a nine-sided polygon