gaudy vs flashy

gaudy is a noun but flashy is not a noun.

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

As adjectives, gaudy and flashy are synonyms defined as:

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

Other synonyms of gaudy include jazzy, showy, sporty.

As adjectives, gaudy and flashy are synonyms defined as:

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

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

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