• synonyms


[non-uh-gon, -guh n]
See more synonyms for nonagon on Thesaurus.com
  1. a polygon having nine angles and nine sides.
Show More

Origin of nonagon

1680–90; < Latin nōn(us) ninth + -a- (extracted from pentagon, hexagon, etc.) + -gon
Also called enneagon.
Related formsnon·ag·o·nal [non-ag-uh-nl] /nɒnˈæg ə nl/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words


Examples from the Web for nonagon

Historical Examples

  • There is said to be only one triangle, only one nonagon, and only one of diamond shape in all the forty thousand.

    One Irish Summer

    William Eleroy Curtis

British Dictionary definitions for nonagon


  1. a polygon having nine sidesAlso called: enneagon
Show More
Derived Formsnonagonal (nɒnˈæɡənəl), adjective
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

Word Origin and History for nonagon


"plane figure with nine sides," 1680s, a hybrid from Latin nonus "ninth" (see nones) + ending from pentagon, etc.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper