Synonyms

nonagon

American

[non-uh-gon, -guhn] / ˈnɒn əˌgɒn, -gən /

noun

a polygon having nine angles and nine sides.

nonagon British

/ nɒnˈæɡənəl, ˈnɒnəˌɡɒn /

noun

Also called: enneagon. a polygon having nine sides

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

nonagonal

adjective

Etymology

Origin of nonagon

1680–90; < Latin nōn ( us ) ninth + -a- (extracted from pentagon, hexagon, etc.) + -gon

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

And in geometry, an enneagon or nonagon is a nine-sided shape.

From BBC • Aug. 23, 2017

Illustrations of the former are the bonds between cube root, hectare, brokerage, commission, indorsement, vertex, adjacent, nonagon, sector, draft, bill of exchange, and their meanings.

From The Psychology of Arithmetic by Thorndike, Edward L. (Edward Lee)

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023