ˈäktəˌgän sometimes -tə̇gən noun
( -s )
Etymology: Latin octagonum, octogonum, from Greek oktagōnon, from neuter of oktagōnos octagonal, from okta- octa- + -gōnos (from gōnia angle); akin to Greek gony knee — more at knee
1. : a plane polygon of eight angles and therefore eight sides — see area table
2. : an octagonal object
the central octagon was covered by a dome — E.H.Short