Etymograph

English

coapt

Coapt comes from Late Latin coaptō ‘to coapt’, from Latin aptō ‘to fasten’, and ultimately from Proto-Indo-European *h₂ep- ‘to join, fit (in)’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂ep-1‘to join, fit (in)’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂ptós1reconstructed
  3. Proto-Italicc. 1500–700 BCE*aptos1reconstructed
  4. Latinc. 75 BCE–200 CEaptus2‘suitable, fitting’
  5. Latinc. 75 BCE–200 CEaptō3‘to fasten’
  6. Late Latinc. 200–600 CEcoaptō3‘to coapt’
  7. Englishtodaycoapt3

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin aptus
  2. 2 Wiktionary, Latin apto
  3. 3 Wiktionary, English coapt

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂ep-Wiktionary, Latin aptus‘to join, fit (in)’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂ptósWiktionary, Latin aptusreconstructed
  3. Proto-Italicc. 1500–700 BCE*aptosWiktionary, Latin aptusreconstructed
  4. Latinc. 75 BCE–200 CEaptusWiktionary, Latin apto‘suitable, fitting’
  5. Latinc. 75 BCE–200 CEaptōWiktionary, English coapt‘to fasten’
  6. Late Latinc. 200–600 CEcoaptōWiktionary, English coapt‘to coapt’
  7. EnglishtodaycoaptWiktionary, English coapt

first attested First attested in 1570 (as stated in Wiktionary’s etymology)

The story

First attested in 1570; Late Latin coaptō, from con- + aptō (‘to fasten’).

Full etymology on Wiktionary

Linked words

through Proto-Indo-European *h₂ep- ‘to join, fit (in)’

apex, ape, aven, 21 more

through Latin aptus ‘suitable, fitting’

apt, aptitude, attitudinal, 10 more

through Latin aptō ‘to fasten’

attitude, adaptation, adapt, 4 more

Today it means

verb To fit together; often, to fit together and fasten, sometimes with mutual adaptation.

Sources

Sources: Wiktionary, “coapt”; the older steps come from the Wiktionary entries for Latin aptus, Latin apto. 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 *h₂ep- / coapt

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