valedictorian vs valedictory speaker

valedictorian and valedictory speaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
valedictorian	Yes	No	No	No
valedictory speaker	Yes	No	No	No

As nouns, valedictorian and valedictory speaker are synonyms defined as:

valedictorian and valedictory speaker: the student with the best grades who usually delivers the valedictory address at commencement

valedictorian (noun)	valedictory speaker (noun)
the student with the best grades who usually delivers the valedictory address at commencement	the student with the best grades who usually delivers the valedictory address at commencement