jurisprudence vs letters of administration

jurisprudence and letters of administration both are nouns.

Word	Noun	Adjective	Verb	Adverb
jurisprudence	Yes	No	No	No
letters of administration	Yes	No	No	No

jurisprudence (noun)	letters of administration (noun)
the branch of philosophy concerned with the law and the principles that lead courts to make the decisions they do	legal document naming someone to administer an estate when no executor has been named
the collection of rules imposed by authority