younker vs juvenile

younker and juvenile both are nouns.

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

As nouns, juvenile is a hypernym of younker; that is, juvenile is a word with a broader meaning than younker:

Other hypernyms of younker include juvenile person.

younker (noun)	juvenile (noun)
a young person (especially a young man or boy)	a young person, not fully developed

younker (adjective)	juvenile (adjective)
	of or relating to or characteristic of or appropriate for children or young people
	displaying or suggesting a lack of maturity