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pactum

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Etymology and origin of the Latin word pactum

Confidence
Established
Formation
Derivation
First attested
c. 450 BC, Twelve Tables
Ultimate origin
Proto-Indo-European (*peh₂ḱ-)

Pronunciation

  • Classical: [ˈpak.tũː][1]
  • Ecclesiastical: [ˈpak.tum][1]

Forms

pactum n (genitive pactī); second declension[1]

Etymology

It is the neuter of the participle of pacīscor (“to make an agreement”) used as a noun.[2][1][3] De Vaan lists it, with the old verb ⟨pacere⟩ and pāx (“peace”), under Proto-Italic *pāk- (“agreement”) and Proto-Indo-European *peh₂ḱ- (“agreement”).[4][1] The TLL treats it with pangō (“to fix”).[5]

Earliest recorded meaning

De Vaan and Köbler record it in the Twelve Tables.[4][6] Plautus already has the adverbial use: sī nōn fēcerō eī male aliquō pactō, “if I don't do him harm somehow”.[2]

Semantic evolution

Pactum is an agreement or compact, Cicero defines it as what has been agreed between people (pactum est quod inter aliquōs convenit).[2][7] In adverbial phrases it means “way, manner”: aliquō pactō “somehow”, nūllō pactō “by no means”, hōc pactō “in this way”.[2][1]

In medieval Latin it was also a treaty document, a barbarian national law code, a royal decree, and a tribute or levy.[8] English pact (early 15th century) comes from it, partly through Old French.[3]

Timeline

  • c. 450 BC – In the Twelve Tables.[4][6]
  • c. 250–184 BC – Plautus: aliquō pactō.[2][6]
  • 81–43 BC – Cicero defines pactum.[2][6]
  • early 15th century – English pact.[3]

Meanings

Noun

  1. An agreement, compact, bargain.[2][7][1]
  2. (in adverbial phrases) Way, manner, means: aliquō pactō, somehow.[2][1]
  3. (Medieval Latin) A treaty document; a law code; a royal decree; a tribute.[8]

References

  1. ^ a b c d e f g h Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ 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
  5. ^ Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
  6. ^ a b c d Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  7. ^ a b Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  8. ^ a b Niermeyer, J. F. (1976), Mediae Latinitatis Lexicon Minus, Leiden: Brill
Cite this entry

“Pactum.” Etymologically, 18 Oct. 2026, etymologically.com/la/pactum. Accessed 19 Oct. 2026.

Last edited on . ·