kickoff vs commencement

kickoff and commencement both are nouns.

Word	Noun	Adjective	Verb	Adverb
kickoff	Yes	No	No	No
commencement	Yes	No	No	No

As nouns, commencement is a hypernym of kickoff; that is, commencement is a word with a broader meaning than kickoff:

kickoff: (football) a kick from the center of the field to start a football game or to resume it after a score
commencement: the act of starting something

Other hypernyms of kickoff include place-kicking, place kick, beginning, start.

As nouns, kickoff and commencement are synonyms defined as:

kickoff and commencement: the time at which something is supposed to begin

Other synonyms of kickoff include beginning, first, get-go, offset, outset, showtime, start, starting time.

kickoff (noun)	commencement (noun)
(football) a kick from the center of the field to start a football game or to resume it after a score	the act of starting something
a start given to contestants	an academic exercise in which diplomas are conferred
the time at which something is supposed to begin	the time at which something is supposed to begin