immature vs juvenile

immature is not a noun while juvenile is a noun.

Word	Noun	Adjective	Verb	Adverb
immature	No	Yes	No	No
juvenile	Yes	Yes	No	No

immature (noun)	juvenile (noun)
	a young person, not fully developed

immature (adjective)	juvenile (adjective)
not yet mature	of or relating to or characteristic of or appropriate for children or young people
characteristic of a lack of maturity	displaying or suggesting a lack of maturity
(used of living things especially persons) in an early period of life or development or growth
(of birds) not yet having developed feathers
not fully developed or mature; not ripe