immature vs unripened

immature and unripened both are adjectives.

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

As adjectives, immature and unripened are synonyms defined as:

Other synonyms of immature include green, unripe.

immature (adjective)	unripened (adjective)
not yet mature	not fully developed or mature; not ripe
characteristic of 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