Etymograph

English

defervescence

Defervescence comes from Latin dēfervēscō ‘to grow cool’, from ferveō ‘to be hot’, and ultimately from Proto-Indo-European *bʰrewh₁- ‘to boil’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*bʰrewh₁-1‘to boil’reconstructed
  2. Proto-Italicc. 1500–700 BCE*ferwejō1reconstructed
  3. Proto-Italicc. 1500–700 BCE*ferweō1reconstructed
  4. Latinc. 75 BCE–200 CEferveō2‘to be hot’
  5. Latinc. 75 BCE–200 CEfervēscō3‘to grow hot’
  6. Latinc. 75 BCE–200 CEdēfervēscō4as defervescere‘to grow cool’
  7. Englishearliest quotation 2003defervescence4

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin ferveo
  2. 2 Wiktionary, Latin fervesco
  3. 3 Wiktionary, Latin defervesco
  4. 4 Wiktionary, English defervescence
  5. Earliest quotation in Wiktionary’s entry: 2003, Cartmell et al.: “Endogenous interleukin-10 is required for the defervescence of fever…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*bʰrewh₁-Wiktionary, Latin ferveo‘to boil’reconstructed
  2. Proto-Italicc. 1500–700 BCE*ferwejōWiktionary, Latin ferveoreconstructed
  3. Proto-Italicc. 1500–700 BCE*ferweōWiktionary, Latin ferveoreconstructed
  4. Latinc. 75 BCE–200 CEferveōWiktionary, Latin fervesco‘to be hot’
  5. Latinc. 75 BCE–200 CEfervēscōWiktionary, Latin defervesco‘to grow hot’
  6. Latinc. 75 BCE–200 CEdēfervēscōWiktionary, English defervescenceas defervescere‘to grow cool’
  7. Englishearliest quotation 2003defervescenceWiktionary, English defervescence. Earliest quotation in Wiktionary’s entry: 2003, Cartmell et al.: “Endogenous interleukin-10 is required for the defervescence of fever…”

Linked words

through Proto-Indo-European *bʰrewh₁- ‘to boil’

brand, burn, bread, purple, brew, bourbon, broth, bourne, brunt, brim, bren, broil, porphyry, briny, purpura, 38 more

through Proto-Italic *ferweō

fervently, 6 more

through Latin ferveō ‘to be hot’

fervor, ferment, fervent, effervescent, 7 more

Today it means

noun The departure or subsiding of a fever.

Sources

Sources: Wiktionary, “defervescence”; the older steps come from the Wiktionary entries for Latin ferveo, Latin fervesco, Latin defervesco. 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 *bʰrewh₁- / defervescence

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