from The American Heritage® Dictionary of the English Language, 4th Edition
- suffix A figure having a specified kind or number of angles: isogon.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- suffix Forms the names of plane figures containing a given number of angles, and thus bounded by that number of line segments (polygons). If the number is large enough, it can be attached directly to an English numeral with a hyphen.
Greek -gōnon, from neuter of gōnos, angled, from gōniā, angle; see genu-1 in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)