Etymologically

Etymology and origin of the Portuguese word lei

Confidence
Established
Formation
Inherited
First attested
1200s Cantigas de Santa Maria More words from the 13th century
Inherited from
Latin lex
Ultimate origin
Proto-Italic *lēg-
Etymology tree
inherited borrowed derived
Latin lēx
French loi
Italian legge
Portuguese lei
Romanian lege
Spanish ley
From the same root
Latin exlēx ← lēx
Latin lēgālis ← lēx
Latin lēgifer ← lēx
Latin lēgislātiō ← lēx
Latin lēgislātor ← lēx
Latin legista ← lēx
Latin lēgitimus ← lēx
Latin legō ← lēx
Latin prīvilēgium ← lēx

Pronunciation

  • Brazil: /ˈlej/, [ˈleɪ̯][1]
  • Portugal: /ˈlɐj/[1]
  • Northern, Portugal: /ˈlej/[1]
  • Central, Portugal: /ˈlej/[1]

Forms

lei f (plural leis)[1] Old Galician-Portuguese wrote lee, lei and ley, and in the 14th and 15th centuries also lley; the plural was leis, lex or leix.[2][3] Feijó (1734) and Bluteau's book of synonyms still give the spellings lei and ley side by side.[4][5]

Etymology

It is inherited from Latin lēx (“law”), written Old Galician-Portuguese lee and Old Galician-Portuguese lei in the oldest texts.[2][1][6][7] The two-syllable form, with the Latin /g/ lost between vowels, stood between the Latin word and the later monosyllable, as in Spanish.[1][8] Houaiss notes that the Latin word, a written and promulgated obligation, was opposed to mōs and cōnsuētūdō, custom or unwritten law.[2]

The same Latin word is Galician lei, Spanish ley, Catalan llei, Occitan lei, French loi, Italian legge and Romanian lege.[9][1]

The Latin word continues Proto-Italic *lēg-.[10] It is usually derived from Proto-Indo-European *leǵ- (“to gather”), the root of legō, but de Vaan marks this with a query.[10][1] Palmer proposed instead *legʰ- (“to lie”), which would make the word parallel to the English law;[11] Fortson accepts that view.[11]

Earliest recorded meaning

Houaiss's first date, 1034 (leys), is a Latin charter, and a Latin text of 1105 has lee et foro de rex de legione “the law and fuero of the king of León”.[2][3] In Galician-Portuguese the word appears in the 13th century, and its first sense there is “religion”: the Cantigas de Santa Maria speak of a servant of God e de sa ley amador “and a lover of his law”, of a lee dos crischãos “the religion of the Christians”, and of the Virgin through whom God nos deu nova lee “gave us a new law”.[12] Pero da Ponte names todas tres las leis, the Jewish, Christian and Muslim faiths.[12]

Semantic evolution

The medieval texts also use the word for the Old Testament (a Vella Lei), for a monastic rule, and for religious belief in general.[12][3] The Portuguese translation of the Fuero Real of Alfonso X already has it in the legal sense.[7] Bluteau's synonyms (decree, statute, ordinance, rule) show the legal sense dominant in the 18th century.[5]

From the legal sense came the scientific one, a constant relation between phenomena (as leis da física), and the rules of an art.[2][13] In coinage lei is the legal proportion of precious metal in an alloy, hence ouro de lei and, by extension, madeira de lei “hardwood of the best quality”.[2][14][13] In Portugal and Galicia the word also meant “affection, esteem”.[2][15][16]

Timeline

  • 1034 – leys in a Latin charter.[2]
  • 1105 – a Latin text has lee et foro.[3]
  • 13th century – ley and lee “religion” in the Cantigas de Santa Maria.[12]
  • 14th century – the spellings lex and lley.[2]
  • 15th century – the plural leix.[2][3]
  • c. 1510 – lei in the Vida de Santo Agostinho (witness 1480–1510).[17]
  • 1697 – Pereira translates Lei as lex, praescriptum, statutum and edictum.[18]
  • 1734 – Feijó gives the spellings Lei, ou Ley.[4]

Meanings

Noun

  1. A law: a rule laid down by the sovereign authority of a state, which all must obey: A nova lei entra em vigor amanhã.[2][19][20]
  2. The body of such rules; the law: Ninguém está acima da lei.[2][20]
  3. A rule imposed by custom, conscience or circumstances.[2][19]
  4. Power, dominion: a lei do mais forte “the law of the strongest”.[2][19]
  5. A norm or principle of an art or a discipline: as leis da harmonia.[2][19]
  6. (science) A constant relation between phenomena: a lei da gravidade.[2][14][13]
  7. (religion) A religious law; a religion: a lei de Moisés.[2][14][13]
  8. The legal proportion of precious metal in an alloy for coinage: ouro de lei.[2][14]
  9. Good quality, genuineness: madeira de lei.[2][13]
  10. (Portugal, regional) Affection, esteem.[2][15]

Word family

  • decreto-lei

Usage notes

Fixed phrases include lei seca “prohibition”, lei da rolha “gag law” and de boa lei “genuine”.[14] In Rio Grande do Sul, lei do embudo (“funnel law”) is a law applied to favour the powerful, a phrase shared with the Spanish of the Plate.[21]

References

  1. ^ a b c d e f g h i Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q r s t Houaiss, Antônio; Villar, Mauro de Salles (2001), Dicionário Houaiss da língua portuguesa, Rio de Janeiro: Objetiva, p. s.v. lei
  3. ^ 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. lee
  4. ^ a b Feijó, João de Morais Madureira (1734), Orthographia, ou Arte de escrever, e pronunciar com acerto a lingua portugueza, Lisboa (CLP transcription, Universidade de Aveiro)
  5. ^ a b Bluteau, Raphael (1712–1728), Vocabulario portuguez e latino, 8 vols. + 2 supplement vols., Coimbra / Lisboa (CLP transcription, Universidade de Aveiro), p. s.v. lei
  6. ^ Nascentes, Antenor (1966), Dicionário etimológico resumido, Rio de Janeiro: Instituto Nacional do Livro, p. s.v. lei
  7. ^ a b Nascentes, Antenor (1955), Dicionário etimológico da língua portuguesa, vol. 1: Nomes comuns, Rio de Janeiro (1st ed. 1932, preface by W. Meyer-Lübke), p. s.v. lei
  8. ^ Corominas, Joan; Pascual, José A. (1980–1991), Diccionario crítico etimológico castellano e hispánico, 6 vols., Madrid: Gredos, p. 3, 639
  9. ^ Meyer-Lübke, Wilhelm (1935), Romanisches etymologisches Wörterbuch, 3rd ed., Heidelberg: Winter
  10. ^ a b de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  11. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org, p. s.v. lex
  12. ^ 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. lei
  13. ^ a b c d e 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. lei
  14. ^ a b c d e Dicionário Priberam da Língua Portuguesa, Lisboa: Priberam Informática, https://dicionario.priberam.org, p. s.v. lei
  15. ^ a b Instituto da Lingua Galega, Tesouro do léxico patrimonial galego e portugués (TLPGP), Santiago de Compostela: Universidade de Santiago de Compostela, https://ilg.usc.gal/tesouro, p. s.v. lei
  16. ^ Estraviz, Isaac Alonso, Dicionário Estraviz, https://estraviz.org, p. s.v. lei
  17. ^ Centro de Linguística da Universidade de Lisboa, CTA – Corpus de Textos Antigos, https://teitok.clul.ul.pt/cta, p. s.v. lei
  18. ^ Pereira, Bento (1697), Thesouro da lingoa portuguesa, in the 1697 edition of his Prosodia (1st ed. 1647; CLP transcription, Universidade de Aveiro)
  19. ^ a b c d Ferreira, Aurélio Buarque de Holanda, Novo dicionário Aurélio da língua portuguesa, digital edition, p. s.v. lei
  20. ^ 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. lei
  21. ^ Schlee, Aldyr Garcia (2019), Dicionário da Cultura Pampeana Sul-Rio-Grandense, 2 vols., Pelotas: Fructos do Paiz, p. s.v. lei

Related etymologies

Cite this entry

“Lei.” Etymologically, 15 Nov. 2026, etymologically.com/pt/lei. Accessed 16 Nov. 2026.

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