flashy vs gaudy

flashy is not a noun while gaudy is a noun.

Word	Noun	Adjective	Verb	Adverb
flashy	No	Yes	No	No
gaudy	Yes	Yes	No	No

As adjectives, flashy and gaudy are synonyms defined as:

flashy and gaudy: (used especially of clothes) marked by conspicuous display

Other synonyms of flashy include jazzy, showy, sporty.

As adjectives, flashy and gaudy are synonyms defined as:

Other synonyms of flashy include brassy, cheap, flash, garish, gimcrack, loud, meretricious, tacky, tatty, tawdry, trashy.

flashy (noun)	gaudy (noun)
	(Britain) a celebratory reunion feast or entertainment held at a college

flashy (adjective)	gaudy (adjective)
(used especially of clothes) marked by conspicuous display	(used especially of clothes) marked by conspicuous display
tastelessly showy	tastelessly showy