Etymologically
Log in

fallax

This is the current revision of this entry, as edited by bogdan on 16 October 2026 at 19:01. This address is a permanent link to this version.
Changes in this edit History

Pronunciation

  • IPA (Classical): [ˈfal.laːks][1]
  • IPA (Ecclesiastical): [ˈfal.laks][1]

Forms

fallāx (genitive fallācis, comparative fallācior, superlative fallācissimus, adverb fallāciter); third-declension one-termination adjective[1] Genitive plural fallācium, but Catullus has fallācum.[2][3]

Etymology

It is from fallō “to deceive” with the suffix -āx “inclined to”.[2][1][4] De Vaan reconstructs ⟨fallō⟩ as Proto-Italic *fal-s-e/o-, perhaps from Proto-Indo-European *sgʷʰh₂(e)l-n- (“to stumble”).[5]

Earliest recorded meaning

Köbler's earliest source is Cato, whom he dates 234–149 BC, and the OLD's first citation is from Lucilius.[6][2]

Semantic evolution

It meant deceitful, treacherous, of persons, as in Cicero; misleading, deceptive, of things, as in Lucilius and Cicero's spēs fallācēs “deceptive hopes”; and not genuine, false, spurious, as in Cicero.[2][7]

In Ecclesiastical Latin it meant deceitful, vain, unreliable, untrustworthy.[8] British Medieval Latin used it for deceitful, false, also as a noun, as in Gildas.[9] Its noun fallācia gave English fallacy in the late 15th century.[4]

Timeline

  • 234–149 BC – Cato uses it.[6]
  • c. 180–102 BC – Lucilius uses it of deceptive things.[2][6]
  • 81–43 BC – Cicero uses it of deceitful persons.[2][6]
  • late 15th century – English fallacy is recorded.[4]

Meanings

Adjective

  1. Deceitful, treacherous.[2]
  2. Misleading, deceptive.[2]
  3. False, spurious.[2]

Word family

References

  1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  3. ^ Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  4. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  5. ^ de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  6. ^ a b c d Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  7. ^ Gaffiot, Félix (2016), Dictionnaire latin-français, new ed. by Gérard Gréco et al. (Gaffiot 2016), online ed.
  8. ^ Stelten, Leo F. (1995), Dictionary of Ecclesiastical Latin, Peabody, Mass.: Hendrickson
  9. ^ 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