phlegm

UK: /ˈflɛm/ US: /flɛm/ ,(flem)

WordReference Random House Learner's Dictionary of American English © 2025

phlegm /flɛm/   n. [uncountable]

1. Pathology the mucus in the nose, mouth, and throat, esp. that appearing in the lungs and throat passages when a person has a cold.
2. calmness;
   composure.

WordReference Random House Unabridged Dictionary of American English © 2025

phlegm  (flem), n. 

1. Pathology the thick mucus secreted in the respiratory passages and discharged through the mouth, esp. that occurring in the lungs and throat passages, as during a cold.
2. one of the four elemental bodily humors of medieval physiology, regarded as causing sluggishness or apathy.
3. sluggishness, indifference, or apathy.
4. self-possession, calmness, or composure.

• Greek phlégma flame, phlegmatic humor, equivalent. to phlég(ein) to burn + -ma resultative noun, nominal suffix
• Late Latin phlegma
• Middle French flemme
• Middle English fleem 1350–1400

phlegm′less, adj. 
Synonyms

• 3. impassivity.

Antonyms

• 3. animation, concern.

Collins Concise English Dictionary © HarperCollins Publishers::

phlegm / flɛm/ noun

1. the viscid mucus secreted by the walls of the respiratory tract
2. one of the four bodily humours
3. apathy; stolidity; indifference
4. self-possession; imperturbability; coolness

Etymology: 14th Century: from Old French fleume, from Late Latin phlegma, from Greek: inflammation, from phlegein to burn

ˈphlegmy adjective