Etymograph

English

incredibility

Incredibility comes from Latin incrēdibilis ‘unbelievable, incredible’, from crēdibilis ‘credible, worthy of belief, believable’, and ultimately from Proto-Indo-European *ḱérddʰeh₁ti.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*ḱérddʰeh₁ti1reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*ḱréddʰeh₁ti1‘to believe, trust’reconstructed
  3. Proto-Italicc. 1500–700 BCE*krezðō1‘to believe’reconstructed
  4. Latinc. 75 BCE–200 CEcrēdō1‘believe’
  5. Latinc. 75 BCE–200 CEcrēdibilis2‘credible, worthy of belief, believable’
  6. Latinc. 75 BCE–200 CEincrēdibilis3‘unbelievable, incredible’
  7. Latinc. 75 BCE–200 CEincredibilitas4
  8. Englishearliest quotation 1857incredibility4

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin credibilis
  2. 2 Wiktionary, Latin incredibilis
  3. 3 Wiktionary, Latin incredibilitas
  4. 4 Wiktionary, English incredibility
  5. Earliest quotation in Wiktionary’s entry: 1857, The British Quarterly Review: “But, as to its contents, who would believe such…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*ḱérddʰeh₁tiWiktionary, Latin credibilisreconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*ḱréddʰeh₁tiWiktionary, Latin credibilis‘to believe, trust’reconstructed
  3. Proto-Italicc. 1500–700 BCE*krezðōWiktionary, Latin credibilis‘to believe’reconstructed
  4. Latinc. 75 BCE–200 CEcrēdōWiktionary, Latin credibilis‘believe’
  5. Latinc. 75 BCE–200 CEcrēdibilisWiktionary, Latin incredibilis‘credible, worthy of belief, believable’
  6. Latinc. 75 BCE–200 CEincrēdibilisWiktionary, Latin incredibilitas‘unbelievable, incredible’
  7. Latinc. 75 BCE–200 CEincredibilitasWiktionary, English incredibility
  8. Englishearliest quotation 1857incredibilityWiktionary, English incredibility. Earliest quotation in Wiktionary’s entry: 1857, The British Quarterly Review: “But, as to its contents, who would believe such…”

Linked words

through Proto-Italic *krezðō ‘to believe’

credited, creditor, accredit, 6 more

through Latin crēdō ‘believe’

credit, creed, credence, credo, incredulous, credulous, incredulity, credulity, 9 more

through Latin crēdibilis ‘credible, worthy of belief, believable’

credible, 2 more

Today it means

noun The quality of being incredible; incredibleness.

Sources

Sources: Wiktionary, “incredibility”; the older steps come from the Wiktionary entries for Latin credibilis, Latin incredibilis, Latin incredibilitas. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *ḱérddʰeh₁ti / incredibility

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