first appearance vs debut

first appearance and debut both are nouns.

Word	Noun	Adjective	Verb	Adverb
first appearance	Yes	No	No	No
debut	Yes	No	Yes	No

As nouns, first appearance and debut are synonyms defined as:

Other synonyms of first appearance include entry, introduction, launching, unveiling.

first appearance (noun)	debut (noun)
the act of beginning something new	the act of beginning something new
	the presentation of a debutante in society

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