1
: a thick, yellowish liquid that is produced in the nose and throat especially when a person has a cold
2
literary
: calmness in a difficult or unpleasant situation
He displayed remarkable phlegm in very dangerous conditions.
Cite this Entry
“Phlegm.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/phlegm. Accessed 15 Apr. 2026.
Copy Citation
