sluggishness vs languor

sluggishness and languor both are nouns.

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

As nouns, sluggishness and languor are synonyms defined as:

Other synonyms of sluggishness include flatness, lethargy, phlegm.

sluggishness (noun)	languor (noun)
inactivity; showing an unusual lack of energy	inactivity; showing an unusual lack of energy
the pace of things that move relatively slowly	a relaxed comfortable feeling
a state of comatose torpor (as found in sleeping sickness)	a feeling of lack of interest or energy
	oppressively still air