Phlegm is a thick secretion of mucous. It's hard to sleep when you have a bad cold and your throat is full of phlegm.

Your body's respiratory system creates phlegm, pronounced "flem," which becomes thicker and more annoying when you're ill. The thick substance you cough up when you have a terrible cold is phlegm. We don't talk about phlegm all that often these days, but it was very important in medieval science — it was thought that too much phlegm led to apathy and laziness, and it was a sign that the body was out of balance.

Definitions of phlegm
  1. noun
    expectorated matter; saliva mixed with discharges from the respiratory passages; in ancient and medieval physiology it was believed to cause sluggishness
    synonyms: sputum
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    type of:
    mucous secretion, mucus
    protective secretion of the mucus membranes; in the gut it lubricates the passage of food and protects the epithelial cells; in the nose and throat and lungs it can make it difficult for bacteria to penetrate the body through the epithelium
  2. noun
    apathy demonstrated by an absence of emotional reactions
    synonyms: emotionlessness, impassiveness, impassivity, indifference, stolidity, unemotionality
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    type of:
    an absence of emotion or enthusiasm
  3. noun
    inactivity; showing an unusual lack of energy
    synonyms: flatness, languor, lethargy, sluggishness
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    type of:
    inactiveness, inactivity, inertia
    a disposition to remain inactive or inert
Word Family

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