jurisprudence vs underage

jurisprudence is a noun but underage is not a noun.

Word	Noun	Adjective	Verb	Adverb
jurisprudence	Yes	No	No	No
underage	No	Yes	No	No

jurisprudence (noun)	underage (noun)
the branch of philosophy concerned with the law and the principles that lead courts to make the decisions they do
the collection of rules imposed by authority

jurisprudence (adjective)	underage (adjective)
	not of legal age
	dependent by virtue of youth