octogonal

English

Adjective

octogonal (comparative more octogonal, superlative most octogonal)

1. Obsolete form of octagonal.

References

• “octogonal”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.

French

Etymology

From octogone +‎ -al.

Pronunciation

• IPA^(key): /ɔk.to.ɡo.nal/

• Audio:

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Adjective

octogonal (feminine octogonale, masculine plural octogonaux, feminine plural octogonales)

1. octagonal

Further reading

• “octogonal”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

Portuguese

Alternative forms

• octagonal

Pronunciation

• (Brazil) IPA^(key): /ok.to.ɡoˈnaw/ [ok.to.ɡoˈnaʊ̯]

 

• (Portugal) IPA^(key): /ɔk.tɔ.ɡuˈnal/ [ɔk.tɔ.ɣuˈnaɫ]

• (Portugal) IPA^(key): /ɔk.tɔ.ɡuˈnal/ [ɔk.tɔ.ɣuˈnaɫ]
  • (Southern Portugal) IPA^(key): /ɔk.tɔ.ɡuˈna.li/

• Rhymes: (Portugal) -al, (Brazil) -aw
• Hyphenation: oc‧to‧go‧nal

Adjective

octogonal m or f (plural octogonais)

1. octagonal

Derived terms

• octogonalmente

Further reading

• “octogonal”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “octogonal”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Romanian

Etymology

Etymology tree

French octogone

Proto-Indo-European *h₂el-

Proto-Indo-European *-is

Proto-Indo-European *h₂élisder.?

Proto-Italic *-ālis

Latin -ālislbor.

Old French -al

Middle French -al

French -al

French octogonalbor.

Romanian octogonal

Borrowed from French octogonal. By surface analysis, octogon + -al.

Adjective

octogonal m or n (feminine singular octogonală, masculine plural octogonali, feminine/neuter plural octogonale)

1. octagonal

Declension

Declension of octogonal

		singular			plural
		masculine	neuter	feminine	masculine	neuter	feminine
nominative- accusative	indefinite	octogonal		octogonală	octogonali	octogonale
	definite	octogonalul		octogonala	octogonalii	octogonalele
genitive- dative	indefinite	octogonal		octogonale	octogonali	octogonale
	definite	octogonalului		octogonalei	octogonalilor	octogonalelor

Spanish

Alternative forms

• octagonal

Etymology

Etymology tree

Proto-Indo-European *oḱtṓw

Proto-Hellenic *oktṓ

Ancient Greek ὀκτώ (oktṓ)

Ancient Greek ὀκτᾰ- (oktă-)

Proto-Indo-European *ǵónu

Proto-Hellenic *gónu

Proto-Hellenic *-ía

Proto-Hellenic *gonwía

Ancient Greek γωνίᾱ (gōníā)

Proto-Indo-European *-os

Proto-Hellenic *-os

Ancient Greek -ος (-os)

Koine Greek ὀκτάγωνος (oktágōnos)bor.

Latin octōgōnuslbor.

Spanish octógono

Proto-Indo-European *h₂el-

Proto-Indo-European *-is

Proto-Indo-European *h₂élisder.?

Proto-Italic *-ālis

Latin -ālis

Spanish -al

Spanish octogonal

From octógono + -al.

Pronunciation

• IPA^(key): /oɡtoɡoˈnal/ [oɣ̞.t̪o.ɣ̞oˈnal]
• Rhymes: -al
• Syllabification: oc‧to‧go‧nal

Adjective

octogonal m or f (masculine and feminine plural octogonales)

1. octagonal

Further reading

• “octogonal”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025