languor vs phlegm

languor and phlegm both are nouns.

Word	Noun	Adjective	Verb	Adverb
languor	Yes	No	No	No
phlegm	Yes	No	No	No

As nouns, languor and phlegm are synonyms defined as:

Other synonyms of languor include flatness, lethargy, sluggishness.

languor (noun)	phlegm (noun)
inactivity; showing an unusual lack of energy	inactivity; showing an unusual lack of energy
a relaxed comfortable feeling	expectorated matter; saliva mixed with discharges from the respiratory passages; in ancient and medieval physiology it was believed to cause sluggishness
a feeling of lack of interest or energy	apathy demonstrated by an absence of emotional reactions
oppressively still air