noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A polygon with nine sides and nine angles; an enneagon.
2. 2
   a nine-sided polygon wordnet

Synonyms

All synonyms

9 gon9-gonenneagonenneagonninenonage

Example

More examples

"A nonagon, sometimes called an enneagon, is a polygon with nine sides."

Etymology

From nona- + -gon.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.