Etymograph

English

probable

Probable comes from Latin probābilis ‘that may be proved, credible’, from probō ‘to test, examine’, and ultimately from Proto-Indo-European *pro-bʰH-wó-s ‘being in front’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*pro-bʰH-wó-s1‘being in front’reconstructed
  2. Proto-Italicc. 1500–700 BCE*proβāō1‘to approve’reconstructed
  3. Latinc. 75 BCE–200 CEprobō2as probāre‘to test, examine’
  4. Latinc. 75 BCE–200 CEprobābilis2‘that may be proved, credible’
  5. Old Frenchc. 842–1400probable2
  6. Middle Englishc. 1150–1500probable2
  7. Englishearliest quotation 1765–1769probable2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin probo
  2. 2 Wiktionary, English probable
  3. Earliest quotation in Wiktionary’s entry: 1765–1769, William Blackstone, Commentaries on the Laws of England: “probable evidence”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*pro-bʰH-wó-sWiktionary, Latin probo‘being in front’reconstructed
  2. Proto-Italicc. 1500–700 BCE*proβāōWiktionary, Latin probo‘to approve’reconstructed
  3. Latinc. 75 BCE–200 CEprobōWiktionary, English probableas probāre‘to test, examine’
  4. Latinc. 75 BCE–200 CEprobābilisWiktionary, English probable‘that may be proved, credible’
  5. Old Frenchc. 842–1400probableWiktionary, English probable
  6. Middle Englishc. 1150–1500probableWiktionary, English probable
  7. Englishearliest quotation 1765–1769probableWiktionary, English probable. Earliest quotation in Wiktionary’s entry: 1765–1769, William Blackstone, Commentaries on the Laws of England: “probable evidence”

Linked words

through Proto-Indo-European *pro-bʰH-wó-s ‘being in front’

probe, probity, 5 more

through Proto-Italic *proβāō ‘to approve’

approve, 14 more

through Latin probō ‘to test, examine’

improve, prove, proof, approbation, 15 more

Today it means

adj Likely or most likely to be true.

Sources

Sources: Wiktionary, “probable”; the older steps come from the Wiktionary entry for Latin probo. 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 *pro-bʰH-wó-s / probable

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