debut vs ushering in

debut and ushering in both are nouns.

Word	Noun	Adjective	Verb	Adverb
debut	Yes	No	Yes	No
ushering in	Yes	No	No	No

As nouns, ushering in is a hyponym of debut; that is, ushering in is a word with a more specific, narrower meaning than debut:

Other hyponyms of debut include induction, product introduction, naturalisation, naturalization.

debut (noun)	ushering in (noun)
the act of beginning something new	the introduction of something new
the presentation of a debutante in society

debut (verb)	ushering in (verb)
appear for the first time in public
make one's debut
present for the first time to the public