Etymograph

English

defectious

Defectious comes from Latin dēfectus, from dēficiō ‘to move away, leave, withdraw, break away’, 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 move away, leave, withdraw, break away’
  7. Latinc. 75 BCE–200 CEdēfectus1
  8. English1500–presentdefect1
  9. Englishearliest quotation a. 1587defectious1

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, English defectious
  2. Earliest quotation in Wiktionary’s entry: a. 1587, Phillip Sidney [i.e., Philip Sidney]: “some one defectious piece”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*dʰeh₁k-Wiktionary, English defectiousreconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*dʰh₁kyétiWiktionary, English defectiousreconstructed
  3. Proto-Italicc. 1500–700 BCE*θakjōWiktionary, English defectiousreconstructed
  4. Proto-Italicc. 1500–700 BCE*fakjōWiktionary, English defectious‘to make’reconstructed
  5. Latinc. 75 BCE–200 CEfacioWiktionary, English defectious‘to make, construct, fashion, frame, build, erect’
  6. Latinc. 75 BCE–200 CEdēficiōWiktionary, English defectious‘to move away, leave, withdraw, break away’
  7. Latinc. 75 BCE–200 CEdēfectusWiktionary, English defectious
  8. English1500–presentdefectWiktionary, English defectious
  9. Englishearliest quotation a. 1587defectiousWiktionary, English defectious. Earliest quotation in Wiktionary’s entry: a. 1587, Phillip Sidney [i.e., Philip Sidney]: “some one defectious piece”

A compound of defect + -ious

Proto-Indo-European *dʰeh₁k-

…

Proto-Italic *fakjō ‘to make’

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

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

Latin dēfectus ‘a failure, lack’

English defect

Linked words

through Proto-Italic *θakjō

effectively, effectiveness, ineffective, affectionate, imperfection, putrefaction, 64 more

through Proto-Italic *fakjō ‘to make’

factor, difficulty, effective, interface, manufacture, perfection, faction, affection, facet, imperfect, affective, effector, deface, affectation, confectionary, 70 more

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

face, fact, difficult, perfect, profit, feature, facility, effect, faculty, affair, sacrifice, efficient, facial, affect, facilitate, feat, infection, superficial, efficacy, facade, fetish, counterfeit, facsimile, infect, hacienda, maleficent, parfait, facies, aficionado, difficile, beautify, confit, beneficent, efficacious, confection, refectory, 85 more

through Latin dēficiō ‘to move away, leave, withdraw, break away’

deficit, deficient, 9 more

Today it means

adj Defective, having defects.

Sources

Sources: Wiktionary, “defectious”. 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- / defectious

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