What is the meaning of Phlegm?

One of the four humors making up the body in ancient and mediaeval medicine; said to be cold and moist, and often identified with mucus.

Viscid mucus produced by the body, later especially mucus expelled from the bronchial passages by coughing.

A watery distillation, especially one obtained from plant matter; an aqueous solution.

Calmness of temperament, composure; also seen negatively, sluggishness, indifference.

Douglas Harper (2001–2024) “phlegm”, in Online Etymology Dictionary.

phlegm”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present.

Hall, Joseph Sargent (1942 March 2) “1. The Vowel Sounds of Stressed Syllables”, in The Phonetics of Great Smoky Mountain Speech (American Speech: Reprints and Monographs; 4), New York: King's Crown Press, →DOI, →ISBN, § 4, page 21.

Source: wiktionary.org