(ˈ)äk|tagən ə l, -taig- adjective
Etymology: alteration (influenced by octagon ) of earlier octogonal, from Middle French, from octogone octagon (from Latin octagonum, octogonum ) + -al
: having eight sides
built a mansion in the shape of an octagon, which started quite a fashion for octagonal houses — Time
• oc·tag·o·nal·ly - ə lē, - ə li adverb