Etymologically

incredibilitas

Etymology and origin of the Latin word incredibilitas

Confidence
Established
Formation
Derivation
First attested
Ulpian
Ultimate origin
Proto-Indo-European (*ḱred-dʰeh₁-)
Etymology tree
inherited borrowed derived
Latin credibilis
English incredible
Latin incredibilitas

Pronunciation

  • IPA (Classical): [ɪŋ.kreː.dɪˈbɪ.lɪ.taːs][1]
  • IPA (Ecclesiastical): [iŋ.kre.diˈbiː.li.tas][1]

Forms

incrēdibilitās f (genitive incrēdibilitātis); third declension[1]

Etymology

It is from Latin incrēdibilis (“incredible”) + -tās, from in- and crēdibilis (“credible”), from crēdō (“to believe”).[2][1] De Vaan traces ⟨crēdō⟩ to Proto-Italic *krezde/o-, from Proto-Indo-European *ḱred-dʰeh₁- (“to place the heart, believe”).[3]

Earliest recorded meaning

Lewis & Short call it post-classical, citing the Digest, where Köbler names Ulpian.[4][5] Köbler dates Ulpian before 223 AD.[5]

Semantic evolution

It meant the quality of being beyond belief, incredibility, as in the Digest, and in the pseudo-Apuleian Asclepius incredulity, disbelief.[2][4][6]

British Medieval Latin used it for disbelief, doubt.[7]

Timeline

  • before 223 AD – Ulpian uses it.[5]

Meanings

Noun

  1. Incredibility.[2]
  2. Incredulity, disbelief.[4][6]

References

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

“Incredibilitas.” Etymologically, 17 Oct. 2026, etymologically.com/la/incredibilitas. Accessed 17 Oct. 2026.

Last edited on . ·