- having eight sides and eight angles
- of or relating to an octagon
WordReference Random House Unabridged Dictionary of American English © 2026
oc•tag•o•nal
(ok tag′ə nl),USA pronunciation adj.
oc•tag′o•nal•ly, adv.
- Mathematicshaving eight angles and eight sides.
- Neo-Latin octōgōnālis, equivalent. to octō- octo- + Greek gōn(ía) angle + -ālis -al1
- octagon + -al, replacing earlier octogonal 1565–75
Collins Concise English Dictionary © HarperCollins Publishers::
octagonal /ɒkˈtæɡənəl/ adj
oc•ta•gon /ˈɑktəˌgɑn, -gən/USA pronunciation
n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2026- Mathematicsa flat, geometrical shape or figure having eight angles and eight sides.
oc•ta•gon
(ok′tə gon′, -gən),USA pronunciation n.
- Mathematicsa polygon having eight angles and eight sides. Also called octangle.
- Greek oktágōnon, noun, nominal use of neuter of oktágōnos octangular; see octa-, -gon
- Latin octagōnon
- 1650–60
'octagonal' also found in these entries (note: many are not synonyms or translations):