languor vs sluggishness

languor and sluggishness both are nouns.

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

As nouns, languor and sluggishness are synonyms defined as:

Other synonyms of languor include flatness, lethargy, phlegm.

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