passionless vs unenthusiastic

passionless and unenthusiastic both are adjectives.

Word	Noun	Adjective	Verb	Adverb
passionless	No	Yes	No	No
unenthusiastic	No	Yes	No	No

passionless (adjective)	unenthusiastic (adjective)
not passionate	not enthusiastic; lacking excitement or ardor
unmoved by feeling