Etymograph

English

defect

Defect comes from Latin dēfectus ‘a failure, lack’, from dēficiō ‘to be exhausted, run out, fail, run out, be…’, and ultimately from Proto-Indo-European *dʰeh₁k-.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*dʰeh₁k-1reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*dʰh₁kyéti1reconstructed
  3. Proto-Italicc. 1500–700 BCE*θakjō1reconstructed
  4. Proto-Italicc. 1500–700 BCE*fakjō1‘to make’reconstructed
  5. Latinc. 75 BCE–200 CEfacio1‘to make, construct, fashion, frame, build, erect’
  6. Latinc. 75 BCE–200 CEdēficiō1‘to be exhausted, run out, fail, run out, be wanting, fail, cease, disappear’
  7. Latinc. 75 BCE–200 CEdēfectus1‘a failure, lack’
  8. Englishearliest quotation 1824defect1

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, English defect
  2. Earliest quotation in Wiktionary’s entry: 1824, Lydia Sigourney: “and the indefatigable application with which they have supplied…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*dʰeh₁k-Wiktionary, English defectreconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*dʰh₁kyétiWiktionary, English defectreconstructed
  3. Proto-Italicc. 1500–700 BCE*θakjōWiktionary, English defectreconstructed
  4. Proto-Italicc. 1500–700 BCE*fakjōWiktionary, English defect‘to make’reconstructed
  5. Latinc. 75 BCE–200 CEfacioWiktionary, English defect‘to make, construct, fashion, frame, build, erect’
  6. Latinc. 75 BCE–200 CEdēficiōWiktionary, English defect‘to be exhausted, run out, fail, run out, be wanting, fail, cease, disappear’
  7. Latinc. 75 BCE–200 CEdēfectusWiktionary, English defect‘a failure, lack’
  8. Englishearliest quotation 1824defectWiktionary, English defect. Earliest quotation in Wiktionary’s entry: 1824, Lydia Sigourney: “and the indefatigable application with which they have supplied…”

The story

Borrowed from Latin defectus (‘a failure, lack’), from deficere (‘to fail, lack, literally 'undo'’), from past participle defectus, from de- (‘of, from’) + facere (‘to do’).

Full etymology on Wiktionary

Linked words

through Proto-Italic *θakjō

affectionate, imperfection, putrefaction, 64 more

through Proto-Italic *fakjō ‘to make’

factor, difficulty, interface, effectively, manufacture, faction, effectiveness, perfection, affection, facet, ineffective, imperfect, affective, deface, affectation, effector, confectionary, 67 more

through Latin facio ‘to make, construct, fashion, frame, build, erect’

face, fact, difficult, profit, feature, facility, perfect, faculty, affair, sacrifice, efficient, effective, facial, effect, facilitate, affect, infection, feat, superficial, efficacy, fetish, counterfeit, facade, facsimile, hacienda, infect, maleficent, aficionado, beautify, parfait, facies, difficile, efficacious, confit, beneficent, confection, refectory, 84 more

through Latin dēficiō ‘to be exhausted, run out, fail, run out, be…’

deficit, deficient, 9 more

Today it means

noun A fault or malfunction.

Sources

Sources: Wiktionary, “defect”. 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 *dʰeh₁k- / defect

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