phlegm

1 of 2

noun

ˈflem 

1

: viscid mucus secreted in abnormal quantity in the respiratory passages

2

: the one of the four humors (see humor sense 2c) in ancient and medieval physiology that was believed to be cold and moist and to cause lethargy and dullness

3

a

: dull or apathetic coldness or indifference

b

: intrepid coolness or calm fortitude

phlegmy

ˈfle-mē 

adjective

phlegmy

2 of 2

adjective

ˈflemē 

-er/-est

: of, constituting, characterized by, or due to phlegm

a phlegmy cough

: phlegmatic

sometimes : watery

Synonyms of phlegm

Noun

• numbness
• impassiveness
• impassivity
• emptiness
• coldness
• apathy

Examples of phlegm in a Sentence

Noun

He displayed remarkable phlegm in very dangerous conditions.

a man of remarkable phlegm, never showing enthusiasm nor displeasure

Recent Examples on the Web

Noun

Veeze’s signature rapping voice, which sounds like his vocal cords are coated in phlegm and cough syrup, is increasingly versatile, despite the sometimes half-asleep delivery. —Matthew Ritchie, Pitchfork, 2 June 2026

In addition, not everyone can produce phlegm easily, including children, the elderly and those weakened by disease. —Ari Daniel, NPR, 29 Apr. 2026

For the Hippocratic doctors, mania was a disease like any other, caused by an imbalance in the four humors: black bile, yellow bile, blood, and phlegm. —Literary Hub, 28 Apr. 2026

And if salt and water start to move, so, too, does the phlegm that has been sitting dehydrated in the lungs of CF patients. —Courtney Crowder, USA Today, 10 Apr. 2026

Word History

Etymology

Noun

Middle English fleume, fleem, flemne "one of the four humors, temperament in which this humor is predominant (alleged to cause indolence or stolidity), bodily discharge, mucus," borrowed from Anglo-French fleume, flume, flegme (continental Old French flegme), borrowed from Late Latin phlegmat-, phlegma, borrowed from Greek phlegmat-, phlégma "flame, fire, inflammation, one of the four humors, white or colorless body secretion (as mucus, saliva)," from phleg-, stem of phlégein "to burn up, consume, kindle, fire up, (intransitive) blaze, gleam" + -mat-, -ma, resultative noun suffix; *phleg- going back to Indo-European *b^hleg- "shine, be bright," whence also, with varying ablaut, Germanic *blak- "flash, shine, burn" (see black entry 1), Latin fulgō, fulgere, later fulgeō, fulgēre "to shine brightly, flash, lighten" (< *b^hl̥g-), Tocharian B palkäṃ "shines," pälketär "burns, glows"

Adjective

phlegm + -y (adjective suffix)

First Known Use

Noun

13th century, in the meaning defined at sense 2

Rhymes for phlegm

• clem
• em
• femme
• gem
• hem
• rem
• stem
• them
• atm
• diadem
• ibidem
• meristem

Kids Definition

phlegm

noun

ˈflem 

1

: thick mucus produced in abnormal quantity in the respiratory passages

2

a

: cold indifference

b

: calm fortitude

phlegmy

ˈflem-ē 

adjective

Medical Definition

phlegm

noun

ˈflem 

1

: viscid mucus secreted in abnormal quantity in the respiratory passages

2

: the one of the four humors (see humor sense 2) of ancient and medieval physiology that was believed to be cold and moist and to cause lethargy and dullness