show-off vs egoist

show-off and egoist both are nouns.

Word	Noun	Adjective	Verb	Adverb
show-off	Yes	No	No	No
egoist	Yes	No	No	No

As nouns, egoist is a hypernym of show-off; that is, egoist is a word with a broader meaning than show-off:

show-off: someone who deliberately behaves in such a way as to attract attention
egoist: a conceited and self-centered person

Other hypernyms of show-off include egotist, swellhead.

show-off (noun)	egoist (noun)
someone who deliberately behaves in such a way as to attract attention	a self-centered person with little regard for others
	a conceited and self-centered person