Etymograph

English

quad-

Quad- comes from Latin quattuor ‘four’, and goes back to Proto-Indo-European *kʷetwṓr.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*kʷetwṓr1reconstructed
  2. Proto-Italicc. 1500–700 BCE*kʷettwōr1‘four’reconstructed
  3. Latinc. 75 BCE–200 CEquattuor2‘four’
  4. Englishtodayquad-2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin quattuor
  2. 2 Wiktionary, English quad-

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*kʷetwṓrWiktionary, Latin quattuorreconstructed
  2. Proto-Italicc. 1500–700 BCE*kʷettwōrWiktionary, Latin quattuor‘four’reconstructed
  3. Latinc. 75 BCE–200 CEquattuorWiktionary, English quad-‘four’
  4. Englishtodayquad-Wiktionary, English quad-

The story

Reduced form of quadri-, from Latin quattuor (‘four’).

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *kʷetwṓr

four, 27 more

through Proto-Italic *kʷettwōr ‘four’

squadron, 25 more

through Latin quattuor ‘four’

square, squad, cater, quarry, cadre, quadrant, quadruple, quadratic, cuatro, quatre, quatrain, quadra, 26 more

Today it means

prefix Involving four elements.

Sources

Sources: Wiktionary, “quad-”; the older steps come from the Wiktionary entry for Latin quattuor. 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 *kʷetwṓr / quad-

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