Etymograph

English

infirm

Infirm comes from Latin infirmus ‘weak, feeble’, from firmus ‘strong, firm’, and ultimately from Proto-Italic *en- ‘in, into, in-’.

  1. Proto-Italicc. 1500–700 BCE*en-1‘in, into, in-’reconstructed
  2. Latinc. 75 BCE–200 CEfirmus1‘strong, firm’
  3. Latinc. 75 BCE–200 CEinfirmus2‘weak, feeble’
  4. Middle Englishc. 1150–1500infirme2
  5. Englishearliest quotation c. 1603–1606infirm2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin infirmus
  2. 2 Wiktionary, English infirm
  3. Earliest quotation in Wiktionary’s entry: c. 1603–1606, William Shakespeare, The Tragedie of King Lear: “[…] Here I stand your slave, A poor, infirm,…”.

Lineage

  1. Proto-Italicc. 1500–700 BCE*en-Wiktionary, Latin infirmus‘in, into, in-’reconstructed
  2. Latinc. 75 BCE–200 CEfirmusWiktionary, Latin infirmus‘strong, firm’
  3. Latinc. 75 BCE–200 CEinfirmusWiktionary, English infirm‘weak, feeble’
  4. Middle Englishc. 1150–1500infirmeWiktionary, English infirm
  5. Englishearliest quotation c. 1603–1606infirmWiktionary, English infirm. Earliest quotation in Wiktionary’s entry: c. 1603–1606, William Shakespeare, The Tragedie of King Lear: “[…] Here I stand your slave, A poor, infirm,…”

Linked words

through Proto-Italic *en- ‘in, into, in-’

impulse, incense, incubation, impel, incubus, incubate, censer, 7 more

through Latin firmus ‘strong, firm’

confirm, affirmative, affirmation, affirming, firmament, 8 more

Today it means

adj Weak or ill, not in good health.

Sources

Sources: Wiktionary, “infirm”; the older steps come from the Wiktionary entry for Latin infirmus. 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-Italic *en- / infirm

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