Etymologically

phlegm

Etymology and origin of the English word phlegm

Pronunciation

  • IPA: /flɛm/[1]

Etymology

It is inherited from Middle English fleume,[2][3][4][5] from Old French fleume,[2][3][4] from Late Latin phlegma,[2][3][4][5][6] from Ancient Greek φλέγμα (phlégma, “flame, inflammation; a humour caused by heat”),[2][3][4][5][6] from phlégein “to burn”.[2][3][4][5][6] Spellings with ph- appear from the 16th century,[7] and the modern form is attested by about 1660.[4]

Earliest recorded meaning

The cold, moist humour of the body (1373–1387).[3][7]

Semantic evolution

In ancient and medieval medicine, phlegm was one of the four humours,[2][1] and an excess of it was thought to cause sluggishness and apathy,[2][4][7] hence phlegmatic.[4] The word also meant mucus from the respiratory passages (before 1398).[3][7] From the 16th century it was used of a calm or sluggish temperament.[1][2]

Timeline

  • 1373 – the cold, moist humour.[3]
  • before 1398 – mucus.[3]
  • 1486 – excess mucus discharged by coughing.[7]
  • about 1660 – the spelling phlegm.[4]

Modern meaning

Noun

  1. Thick, sticky mucus produced in the throat and lungs, as during a cold.
  2. (history) One of the four humours of ancient physiology, thought to be cold and moist and to cause sluggishness.
  3. Sluggishness or apathy.
  4. Calm self-possession; composure.

Word family

  • phlegmy
  • phlegmatic
  • flame

Usage notes

Random House gives impassivity as a synonym of the sense “apathy”, and animation and concern as antonyms.[6]

References

  1. ^ a b c Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
  3. ^ a b c d e f g h i Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
  4. ^ a b c d e f g h i Harper, Douglas, Online Etymology Dictionary, https://www.etymonline.com
  5. ^ a b c d Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
  6. ^ a b c d Random House Webster's Unabridged Dictionary (1999), 2nd ed., New York: Random House
  7. ^ a b c d e Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press

Related etymologies

Cite this entry

“Phlegm.” Etymologically, 11 Oct. 2026, etymologically.com/en/phlegm. Accessed 11 Oct. 2026.

Last edited on . ·