Etymologically

Etymology and origin of the Portuguese word oito

Confidence
Established
Formation
Inherited
First attested
1270 a charter, spelt oyto More words from the 13th century
Inherited from
Latin octo
Ultimate origin
Proto-Indo-European *oḱtṓw
Etymology tree
inherited borrowed derived
Latin octō
French huit
Italian otto
Portuguese oito
Romanian opt
Spanish ocho
From the same root
Latin Octōber ← octō
Latin octōgintā ← octō
Latin octōnus ← octō

Pronunciation

  • Brazil: /ˈoj.tu/, [ˈoɪ̯.tu][1]
  • Portugal: /ˈoj.tu/[1]
  • /ˈøt/[1]

Forms

oito m or f[1] Old forms are oyto, ouito (1365) and the Latinising octo.[2][3] The variant outo, recorded in 1720, is given by Bluteau beside oito.[2][4][1]

Etymology

It is inherited from Latin octō (“eight”), written Old Galician-Portuguese oito and oyto in the oldest texts.[2][3][5][1]

The same Latin word is Galician oito, Spanish ocho, Catalan vuit, French huit, Italian otto and Romanian opt.[6][1]

The Latin numeral continues Proto-Italic *oktō.[7][1] Wiktionary reconstructs Proto-Indo-European *oḱtṓw and de Vaan *h₃(e)ḱtéh₃.[7][1] Cognates include Ancient Greek ὀκτώ (oktṓ), Sanskrit अष्ट (aṣṭa), Gothic 𐌰𐌷𐍄𐌰𐌿 (ahtau) and Lithuanian aštuonì.[7][1] The ending looks like a dual, and some scholars explain the number as “two fours”.[1]

Earliest recorded meaning

A charter of 1270 dates itself En era de mill et ccco et oyto ãnos.[3] The Cantigas de Santa Maria have dez e oito “eighteen”, and another cantiga speaks of oito dias, a week.[8][9]

Semantic evolution

Besides the number, oito names the figure 8, the eight in a pack of cards and a mark of eight in an examination.[10][11] Oito dias means a week, as it already did in the cantigas.[12][9] The expression ou oito ou oitenta “either eight or eighty” means “all or nothing”.[12][13] In Rio Grande do Sul oito is a figure of the country dances, and in the north of Brazil tomar um oito means to get drunk.[14][12]

Timeline

  • 1270 – oyto in a charter.[3]
  • 13th century – dez e oito in the Cantigas de Santa Maria.[8]
  • 1365 – the form ouito.[2]
  • 1496 – first record in the CTA, in the História de mui nobre Vespasiano.[15]
  • 1697 – Pereira glosses oito with Latin octo.[16]
  • 1720 – the form outo.[2]
  • 1789 – Morais defines it as “twice four”.[17]

Meanings

Numeral

  1. eight, the number after seven: oito cadeiras.[2][13][1]
  2. Eighth, of a thing numbered eight in a series: o capítulo oito.[2][10][1]

Noun

  1. The number or figure 8.[10][1]
  2. A playing card, domino or face of a die with eight spots.[13][1]
  3. A mark of eight in an examination.[10][11]

Word family

  • dezoito
  • oitocentos

Usage notes

Ou oito ou oitenta “either eight or eighty” means “all or nothing”, and nem oito nem oitenta “neither one extreme nor the other”.[13][18][1] In Portugal estar feito num oito means to be worn out or in a bad state.[13]

References

  1. ^ a b c d e f g h i j k l m n o p Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g Houaiss, Antônio; Villar, Mauro de Salles (2001), Dicionário Houaiss da língua portuguesa, Rio de Janeiro: Objetiva, p. s.v. oito
  3. ^ a b c d Instituto da Lingua Galega, Dicionario de dicionarios do galego medieval (DDGM), ed. Ernesto González Seoane, Santiago de Compostela: Universidade de Santiago de Compostela, https://ilg.usc.gal/ddgm, p. s.v. oyto
  4. ^ Bluteau, Raphael (1712–1728), Vocabulario portuguez e latino, 8 vols. + 2 supplement vols., Coimbra / Lisboa (CLP transcription, Universidade de Aveiro), p. s.v. oito
  5. ^ Nascentes, Antenor (1966), Dicionário etimológico resumido, Rio de Janeiro: Instituto Nacional do Livro, p. s.v. oito
  6. ^ Meyer-Lübke, Wilhelm (1935), Romanisches etymologisches Wörterbuch, 3rd ed., Heidelberg: Winter, p. 6035
  7. ^ a b c de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  8. ^ a b Instituto da Lingua Galega, Dicionario de dicionarios do galego medieval (DDGM), ed. Ernesto González Seoane, Santiago de Compostela: Universidade de Santiago de Compostela, https://ilg.usc.gal/ddgm, p. s.v. oito
  9. ^ a b Universo Cantigas: Glosario da poesía medieval profana galego-portuguesa, A Coruña: Instituto da Lingua e Literatura (ILLA), Universidade da Coruña, https://www.universocantigas.gal, p. s.v. oito
  10. ^ a b c d Ferreira, Aurélio Buarque de Holanda, Novo dicionário Aurélio da língua portuguesa, digital edition, p. s.v. oito
  11. ^ a b Academia das Ciências de Lisboa, Dicionário da Língua Portuguesa, revised online edition (2023–) of the Dicionário da Língua Portuguesa Contemporânea (2001), https://dicionario.acad-ciencias.pt, p. s.v. oito
  12. ^ a b c Aulete, Francisco Júlio Caldas, Dicionário contemporâneo da língua portuguesa (1st ed. 1881), online as Aulete Digital, Rio de Janeiro: Lexikon, https://aulete.com.br, p. s.v. oito
  13. ^ a b c d e Porto Editora (2013), Grande Dicionário da Língua Portuguesa, Porto: Porto Editora, p. 6655
  14. ^ Schlee, Aldyr Garcia (2019), Dicionário da Cultura Pampeana Sul-Rio-Grandense, 2 vols., Pelotas: Fructos do Paiz, p. s.v. oito
  15. ^ Centro de Linguística da Universidade de Lisboa, CTA – Corpus de Textos Antigos, https://teitok.clul.ul.pt/cta, p. s.v. oito
  16. ^ Pereira, Bento (1697), Thesouro da lingoa portuguesa, in the 1697 edition of his Prosodia (1st ed. 1647; CLP transcription, Universidade de Aveiro), p. s.v. oito
  17. ^ Silva, António de Morais (1789), Diccionario da lingua portugueza composto pelo padre D. Rafael Bluteau, reformado, e accrescentado, 2 vols., Lisboa: Simão Thaddeo Ferreira, p. 2, 130
  18. ^ Michaelis: Moderno Dicionário da Língua Portuguesa, São Paulo: Melhoramentos (online as Michaelis Dicionário Brasileiro da Língua Portuguesa, https://michaelis.uol.com.br), p. s.v. oito

Related etymologies

Cite this entry

“Oito.” Etymologically, 15 Nov. 2026, etymologically.com/pt/oito. Accessed 16 Nov. 2026.

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