valedictory vs exaugural

valedictory is a noun but exaugural is not a noun.

Word	Noun	Adjective	Verb	Adverb
valedictory	Yes	Yes	No	No
exaugural	No	Yes	No	No

valedictory (noun)	exaugural (noun)
a farewell oration (especially one delivered during graduation exercises by an outstanding member of a graduating class)

valedictory (adjective)	exaugural (adjective)
of or relating to an occasion or expression of farewell	occurring at or marking the close of a term of office
of a speech expressing leave-taking