cheap vs gaudy

cheap is not a noun while gaudy is a noun.

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

As adjectives, cheap and gaudy are synonyms defined as:

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

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

cheap (adjective)	gaudy (adjective)
relatively low in price or charging low prices	(used especially of clothes) marked by conspicuous display
of very poor quality; flimsy	tastelessly showy
embarrassingly stingy
tastelessly showy