lassitude vs sluggishness

lassitude and sluggishness both are nouns.

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

As nouns, lassitude and sluggishness are synonyms defined as:

lassitude and sluggishness: a state of comatose torpor (as found in sleeping sickness)

Other synonyms of lassitude include lethargy.

lassitude (noun)	sluggishness (noun)
weakness characterized by a lack of vitality or energy	inactivity; showing an unusual lack of energy
a feeling of lack of interest or energy	the pace of things that move relatively slowly
a state of comatose torpor (as found in sleeping sickness)	a state of comatose torpor (as found in sleeping sickness)