[1] : The Collaborative International Dictionary of English v.0.48

octagon \oc"tagon\, n. gr. ? eight-cornered; 'okta- for
   'oktw` eight + ? an angle: cf. f. cctogone.
   1. geom. a plane figure of eight sides and eight angles.
      1913 webster

   2. any structure as a fortification or place with eight
      sides or angles.
      1913 webster

   regular octagon, one in which the sides are all equal, and
      the angles also are all equal.
      1913 webster
see also:
regular octagon 

[2] : WordNet (r) 2.0

octagon
     n : an eight-sided polygon

Octagon >> O Words
Octagon, definition of term: Octagon
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