Etymologically

Etymology and origin of the Portuguese word casto

Confidence
Established
Formation
Inherited
First attested
1200s Cantigas de Santa Maria More words from the 13th century
Inherited from
Latin castus
Ultimate origin
Latin castus
Etymology tree
inherited borrowed derived
Latin castus
Portuguese casto
Old French chaste
English chaste
Derivations
From the same root
Latin caste ← castus
Latin castīgō ← castus
Latin castīmōnia ← castus
Latin castitās ← castus
Latin incestus ← castus
English unchaste ← chaste

Pronunciation

  • Brazil: /ˈkas.tu/[1]
  • Rio-de-Janeiro: /ˈkaʃ.tu/[1]
  • Portugal: /ˈkaʃ.tu/[1]

Forms

casto (feminine casta, masculine plural castos, feminine plural castas)[1]

Etymology

It is inherited from Latin castus (“pure, chaste”), written Old Galician-Portuguese casto in the oldest texts.[2][3][4][1] Wiktionary notes that it may have been taken from Latin rather than inherited, and the DCECH treats the Spanish word as a learned borrowing.[1][5]

The same Latin word is Galician casto, Spanish casto, Catalan cast, Occitan cast, French chaste and Italian casto.[6][7]

De Vaan lists the Latin adjective, “free from, pure, chaste”, among the derivatives of Latin careō (“to lack, be without”), together with castīgō (“to correct, chasten”) and cassus (“devoid of”), and reconstructs Proto-Italic *kas-ē- (“to lack”).[8] The OLD too calls it perhaps a participle of the verb, and its first sense is “free from, untouched by”.[9] Older works connected it instead with Ancient Greek καθαρός (katharós, “pure”) and a root for “to cleanse”.[10][11]

Earliest recorded meaning

The Cantigas de Santa Maria have un monge bõo, cast' e mui fiel “a good monk, chaste and very faithful”, and the heading of cantiga 137 tells how Holy Mary made chaste (fez seer casto) a knight who had been very lustful.[4] Houaiss and Cunha date the word to the 13th century.[2][3] The medieval texts already use it of sexual restraint and of moral purity, as in the Rule of Saint Benedict, where the abbot must be casto, tẽperado, misericordioso.[4]

Semantic evolution

The Crónica Geral uses the word in the name of King Alfonso II “the Chaste”.[4] Morais (1789) adds the figurative senses “pure”, as in casta lenha in a passage he cites from the Eneida, and “untouched, unharmed”, as in a house left casta by the artillery.[12] Aulete's original edition also has “unmixed”.[13] Houaiss records modern figurative senses: of a style or work of art marked by purity and restraint, and of something kept away from what is impure.[2]

As a man's name, Casto is the adjective.[14]

Timeline

  • 13th century – the Cantigas de Santa Maria use casto of a monk and a knight.[4][2]
  • c. 1430 – the Horto do Esposo (copied 1390–1437) has the word.[15]
  • 1712–1728 – Bluteau defines it as one who keeps or professes chastity.[16]
  • 1789 – Morais adds the figurative senses “pure” and “untouched”.[12]

Meanings

Adjective

  1. chaste: abstaining from all sexual activity.[2][17][1]
  2. Abstaining from sexual relations considered unlawful or immoral.[2][18]
  3. (by extension) Pure, innocent.[2][17]
  4. (figurative) Modest, demure: of dress or behaviour.[2][19]
  5. (figurative) Unmixed, unalloyed; untouched, intact.[2][20]
  6. (figurative) Of style or art: marked by purity and restraint.[2]

Usage notes

The noun casta “race, lineage” has a disputed origin: Diez and the REW refer it to the Latin adjective, while Corominas thinks it may come from Gothic.[7][6]

References

  1. ^ a b c d e f g Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j Houaiss, Antônio; Villar, Mauro de Salles (2001), Dicionário Houaiss da língua portuguesa, Rio de Janeiro: Objetiva, p. s.v. casto
  3. ^ a b Cunha, Antônio Geraldo da (2010), Dicionário etimológico da língua portuguesa, 4th ed., Rio de Janeiro: Lexikon, p. s.v. casto
  4. ^ a b c d e 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. casto
  5. ^ Corominas, Joan; Pascual, José A. (1980–1991), Diccionario crítico etimológico castellano e hispánico, 6 vols., Madrid: Gredos, p. 1, 917
  6. ^ a b Meyer-Lübke, Wilhelm (1935), Romanisches etymologisches Wörterbuch, 3rd ed., Heidelberg: Winter, p. 1751
  7. ^ a b García de Diego, Vicente (1985), Diccionario etimológico español e hispánico, 2nd ed., Madrid: Espasa-Calpe (1st ed. 1954), p. s.v. castus
  8. ^ de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill, p. s.v. careō
  9. ^ Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press, p. s.v. castus
  10. ^ Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press, p. s.v. castus
  11. ^ Vieira, Frei Domingos (1871–1874), Grande Diccionario Portuguez ou Thesouro da lingua portugueza, 5 vols., Porto: Ernesto Chardron e Bartholomeu H. de Moraes, p. 2, 139
  12. ^ a b 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. 1, 244
  13. ^ 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. casto
  14. ^ Nascentes, Antenor (1952), Dicionário etimológico da língua portuguesa, vol. 2: Nomes próprios, Rio de Janeiro, p. s.v. casto
  15. ^ Centro de Linguística da Universidade de Lisboa, CTA – Corpus de Textos Antigos, https://teitok.clul.ul.pt/cta, p. s.v. casto
  16. ^ Bluteau, Raphael (1712–1728), Vocabulario portuguez e latino, 8 vols. + 2 supplement vols., Coimbra / Lisboa (CLP transcription, Universidade de Aveiro), p. s.v. casto
  17. ^ 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. casto
  18. ^ Ferreira, Aurélio Buarque de Holanda, Novo dicionário Aurélio da língua portuguesa, digital edition, p. s.v. casto
  19. ^ Dicionário Priberam da Língua Portuguesa, Lisboa: Priberam Informática, https://dicionario.priberam.org, p. s.v. casto
  20. ^ 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. casto

Related etymologies

Cite this entry

“Casto.” Etymologically, 15 Nov. 2026, etymologically.com/pt/casto. Accessed 16 Nov. 2026.

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