Etymologically

Etymology and origin of the Latin word complex

Confidence
Established
Formation
Derivation
First attested
297–310 Arnobius More words from the 3rd century
Ultimate origin
Latin plicō
Etymology tree
inherited borrowed derived
Latin plicō
Italian piegare
Old French ploiier
Romanian pleca
Spanish llegar
Latin complex
Romanian complice
From the same root
English ply ← plicō
Latin applicō ← plicō
Latin complicō ← plicō
Latin dēplicō ← plicō
Latin displicō ← plicō
Latin explicō ← plicō
Latin implicō ← plicō
Latin replicō ← plicō
Romanian explica ← plicō
Italian piega ← piegare
English pliers ← ploiier
Romanian plecare ← pleca

Pronunciation

  • Classical: [ˈkɔm.pɫɛks][1]
  • Ecclesiastical: [ˈkɔm.pleks][1]

Forms

complex (genitive complicis); third-declension one-termination adjective[1]

Etymology

It is from Latin con- + plicō (“to fold”).[1][2] The TLL compares complicō (“to fold together”) and the adjectives simplex and multiplex.[3]

Earliest recorded meaning

Its earliest record is in Arnobius (297–310 AD),[2] who reports Varro's view of gods dwelling in the innermost recesses of heaven, called consentes et complices, “agreeing and associated”.[3][4]

Semantic evolution

It is a Late Latin word,[4] used as an adjective, “closely connected with, sharing in”, often with a genitive, by Christian writers and in the laws,[4][5] and as a noun for a partner or colleague; the glosses explain it as socii and conscii.[3]

In Medieval Latin it named a copartner, a follower or partisan, and above all an accomplice.[6][7] Old French took it as complice, “a confederate, partner”, without a criminal sense;[8] English borrowed that as complice in the early 15th century, and accomplice (1580s) is an unetymological extension of it.[8]

Timeline

  • 297–310 AD – Arnobius uses it of the gods called consentes et complices.[3][2]
  • c. 340–397 AD – Ambrose uses it with a genitive.[4][2]
  • 348/49–c. 413 AD – Prudentius uses it in the Hamartigenia.[4][2]
  • early 8th century AD – Bede writes that Eve made her husband an accomplice in her transgression.[7][2]
  • early 15th century – English borrows complice through Old French.[8]

Meanings

Adjective

  1. Closely connected (with someone), confederate; sharing in (with genitive).[4][5][9]
  2. Of gods: dii consentes et complices, gods agreeing and associated together.[4]

Noun

  1. A partner, associate, colleague.[3][2]
  2. (Late Latin) An accomplice, a partner in wrongdoing.[9][6][7]
  3. (Medieval Latin) A copartner in business.[6]
  4. (Medieval Latin) A partisan, follower, comrade.[6]

References

  1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  3. ^ a b c d e Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
  4. ^ a b c d e f g Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  5. ^ a b Georges, Karl Ernst (1913–1918), Ausführliches lateinisch-deutsches Handwörterbuch, 8th ed., ed. Heinrich Georges, Hannover; Leipzig: Hahn
  6. ^ a b c d Niermeyer, J. F. (1976), Mediae Latinitatis Lexicon Minus, Leiden: Brill
  7. ^ a b c Latham, R. E., D. R. Howlett, R. K. Ashdowne, et al. (1975–2013), Dictionary of Medieval Latin from British Sources, London: British Academy / Oxford University Press
  8. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  9. ^ a b Stelten, Leo F. (1995), Dictionary of Ecclesiastical Latin, Peabody, Mass.: Hendrickson
Cite this entry

“Complex.” Etymologically, 13 Nov. 2026, etymologically.com/la/complex. Accessed 14 Nov. 2026.

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