Etymograph

English

cooperate

Cooperate comes from Late Latin cooperātus ‘having worked together with another’, from cooperor ‘to work with’, and ultimately from Proto-Indo-European *h₃ep-.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₃ep-1‘to work, toil, make’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₃épos1‘work’reconstructed
  3. Proto-Italicc. 1500–700 BCE*opos1‘work’reconstructed
  4. Latinc. 75 BCE–200 CEopus1‘work, labor, accomplishment’
  5. Latinc. 75 BCE–200 CEopera1
  6. Latinc. 75 BCE–200 CEoperātus1‘having worked, laboured, toiled’
  7. Latinc. 75 BCE–200 CEoperor2‘to work, labor’
  8. Late Latinc. 200–600 CEcooperor3‘to work with’
  9. Late Latinc. 200–600 CEcooperātus3‘having worked together with another’perfect passive participle of cooperor
  10. Englishearliest quotation 2012cooperate3

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin operor
  2. 2 Wiktionary, Latin cooperor
  3. 3 Wiktionary, English cooperate
  4. Earliest quotation in Wiktionary’s entry: 2012, Matt Bai, Winning a Second Term, Obama Will Confront Familiar Headwind: “In polling by the Pew Research Center in November…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₃ep-Wiktionary, Latin operor‘to work, toil, make’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₃éposWiktionary, Latin operor‘work’reconstructed
  3. Proto-Italicc. 1500–700 BCE*oposWiktionary, Latin operor‘work’reconstructed
  4. Latinc. 75 BCE–200 CEopusWiktionary, Latin operor‘work, labor, accomplishment’
  5. Latinc. 75 BCE–200 CEoperaWiktionary, Latin operor
  6. Latinc. 75 BCE–200 CEoperātusWiktionary, Latin operor‘having worked, laboured, toiled’
  7. Latinc. 75 BCE–200 CEoperorWiktionary, Latin cooperor‘to work, labor’
  8. Late Latinc. 200–600 CEcooperorWiktionary, English cooperate‘to work with’
  9. Late Latinc. 200–600 CEcooperātusWiktionary, English cooperate‘having worked together with another’perfect passive participle of cooperor
  10. Englishearliest quotation 2012cooperateWiktionary, English cooperate. Earliest quotation in Wiktionary’s entry: 2012, Matt Bai, Winning a Second Term, Obama Will Confront Familiar Headwind: “In polling by the Pew Research Center in November…”

Formed from co- + operate

Proto-Indo-European *ḱóm ‘beside, near, by, with’

Proto-Italic *kom ‘with, along, at’

Proto-Italic *kom- ‘together’

English co-

Proto-Indo-European *h₃ep- ‘to work’

…

Proto-Italic *opos ‘work’

Latin opus ‘work’

Latin opera

Latin operātus ‘having worked’

English operate

The story

Originated 1595–1605 from Late Latin cooperātus, perfect passive participle of cooperor (‘to work with’), see -ate (verb-forming suffix) for more.

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *h₃ep- ‘to work, toil, make’

office, official, bus, copy, omnibus, copious, opulence, officiate, omnivore, officiant, officious, 22 more

through Latin opus ‘work, labor, accomplishment’

opus, 10 more

through Latin opera

opera, ure, oeuvre, operetta, 9 more

through Latin operor ‘to work, labor’

operation, operator, operative, 3 more

Today it means

verb To work or act together, especially for a common purpose or benefit.

Sources

Sources: Wiktionary, “cooperate”; the older steps come from the Wiktionary entries for Latin operor, Latin cooperor. 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 *h₃ep- / cooperate

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