nipper vs juvenile

nipper and juvenile both are nouns.

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

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

Other hypernyms of nipper include juvenile person.

nipper (noun)	juvenile (noun)
a grasping structure on the limb of a crustacean or other arthropods	a young person, not fully developed
a young person of either sex

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