Etymograph

English

certainty

Certainty comes from Latin certus ‘certain’, and goes back to Proto-Indo-European *krey- ‘to sift, separate, divide’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*krey-1‘to sift, separate, divide’reconstructed
  2. Proto-Italicc. 1500–700 BCE*kritos1reconstructed
  3. Latinc. 75 BCE–200 CEcertus2‘certain’
  4. Vulgar Latinc. 100–700 CE*certānitās2reconstructed
  5. Old Frenchc. 842–1400certeinete2
  6. Anglo-Normanc. 1066–1400certeinte2
  7. Middle Englishc. 1150–1500certeynte2‘surety’
  8. Englishearliest quotation 1720certainty2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin certus
  2. 2 Wiktionary, English certainty
  3. Earliest quotation in Wiktionary’s entry: 1720, Samuel Fancourt, The Remarker's second Objection produced and examined: “That there may be Certainty upon an infallible Evidence…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*krey-Wiktionary, Latin certus‘to sift, separate, divide’reconstructed
  2. Proto-Italicc. 1500–700 BCE*kritosWiktionary, Latin certusreconstructed
  3. Latinc. 75 BCE–200 CEcertusWiktionary, English certainty‘certain’
  4. Vulgar Latinc. 100–700 CE*certānitāsWiktionary, English certaintyreconstructed
  5. Old Frenchc. 842–1400certeineteWiktionary, English certainty
  6. Anglo-Normanc. 1066–1400certeinteWiktionary, English certainty
  7. Middle Englishc. 1150–1500certeynteWiktionary, English certainty‘surety’
  8. Englishearliest quotation 1720certaintyWiktionary, English certainty. Earliest quotation in Wiktionary’s entry: 1720, Samuel Fancourt, The Remarker's second Objection produced and examined: “That there may be Certainty upon an infallible Evidence…”

Linked words

through Proto-Indo-European *krey- ‘to sift, separate, divide’

secret, crime, crisis, criminal, discrimination, critic, discretion, critique, discrete, riddle, discreet, hypocrite, discriminate, criterion, endocrine, discern, excrement, excretion, rime, incriminate, excrete, incrimination, recrimination, ridder, criterium, 45 more

through Latin certus ‘certain’

ascertain, certitude, 6 more

Today it means

noun The state of being certain.

Sources

Sources: Wiktionary, “certainty”; the older steps come from the Wiktionary entry for Latin certus. 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 *krey- / certainty

Shirt and support for this word