Etymologically

incredibiliter

Etymology and origin of the Latin word incredibiliter

Confidence
Established
Formation
Derivation
First attested
81–43 BC, Cicero
Ultimate origin
Proto-Indo-European *ḱred-dʰeh₁-
Etymology tree
inherited borrowed derived
Latin credibilis
English incredible
Italian incredibile
Latin incredibiliter
From the same root
Latin credibiliter ← credibilis
Latin incredibilitas ← incredibilis

Forms

incrēdibiliter (comparative incrēdibilius)[1][2]

Etymology

It is from Latin incrēdibilis (“incredible”) + -ter.[3][4] The adjective is the negative of crēdibilis (“believable”), made from crēdō (“to believe”), which de Vaan traces to Proto-Italic *krezde/o- and Proto-Indo-European *ḱred-dʰeh₁- (“to place in the heart, believe”).[5] Cognate with Welsh credu (“to believe”) and Sanskrit श्रद्धा (śraddhā́-, “confidence, devotion”).[5]

Earliest recorded meaning

Cicero is its first author.[4] In the Philippics he speaks of the will of the whole Roman people agreeing to an extraordinary degree, incrēdibiliter cōnsentientem populī Rōmānī ūniversī voluntātem, and in a letter to Atticus he writes that someone was incredibly frightened, incrēdibiliter pertimuit.[3][1]

Semantic evolution

Besides the literal sense, in a way that is hard to believe,[3][2] it was mostly used as an intensifier, to an extraordinary degree: so in Cicero, in the Bellum Africum of soldiers scattering, and in Tacitus' Dialogus.[3][1] Augustine has the comparative incrēdibilius.[2]

In British Medieval Latin it kept both the literal and the weakened sense.[6]

Timeline

  • 81–43 BC – Cicero uses it to mean “to an extraordinary degree”.[3][4]
  • 98–115 AD – Tacitus uses it in the Dialogus.[1][4]
  • 354–430 AD – Augustine uses the comparative incrēdibilius.[2][4]

Meanings

Adverb

  1. In a way that is hard to believe, incredibly.[3][2]
  2. To an extraordinary degree, extraordinarily.[3][1]

References

  1. ^ a b c d e Conte, Gian Biagio; Pianezzola, Emilio; Ranucci, Giuliano (2010), il Latino: Vocabolario della lingua latina, 3rd ed., Florence: Le Monnier
  2. ^ a b c d e Georges, Karl Ernst (1913–1918), Ausführliches lateinisch-deutsches Handwörterbuch, 8th ed., ed. Heinrich Georges, Hannover; Leipzig: Hahn
  3. ^ a b c d e f g Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  4. ^ a b c d e Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
  5. ^ 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
  6. ^ 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
Cite this entry

“Incredibiliter.” Etymologically, 21 Oct. 2026, etymologically.com/la/incredibiliter. Accessed 22 Oct. 2026.

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