commencement ceremony vs graduation exercise

commencement ceremony and graduation exercise both are nouns.

Word	Noun	Adjective	Verb	Adverb
commencement ceremony	Yes	No	No	No
graduation exercise	Yes	No	No	No

As nouns, commencement ceremony and graduation exercise are synonyms defined as:

commencement ceremony and graduation exercise: an academic exercise in which diplomas are conferred

Other synonyms of commencement ceremony include commencement, commencement exercise, graduation.

commencement ceremony (noun)	graduation exercise (noun)
an academic exercise in which diplomas are conferred	an academic exercise in which diplomas are conferred