ostentatious vs flamboyant

ostentatious is not a noun while flamboyant is a noun.

Word	Noun	Adjective	Verb	Adverb
ostentatious	No	Yes	No	No
flamboyant	Yes	Yes	No	No

ostentatious (noun)	flamboyant (noun)
	showy tropical tree or shrub native to Madagascar; widely planted in tropical regions for its immense racemes of scarlet and orange flowers; sometimes placed in genus Poinciana

ostentatious (adjective)	flamboyant (adjective)
intended to attract notice and impress others	elaborately or excessively ornamented
(of a display) tawdry or vulgar	marked by ostentation but often tasteless