eighteen vs cardinal

eighteen and cardinal both are nouns.

Word	Noun	Adjective	Verb	Adverb
eighteen	Yes	Yes	No	No
cardinal	Yes	Yes	No	No

eighteen (noun)	cardinal (noun)
the cardinal number that is the sum of seventeen and one	crested thick-billed North American finch having bright red plumage in the male
	a variable color averaging a vivid red
	(Roman Catholic Church) one of a group of more than 100 prominent bishops in the Sacred College who advise the Pope and elect new Popes
	the number of elements in a mathematical set; denotes a quantity but not the order

eighteen (adjective)	cardinal (adjective)
being one more than seventeen	being or denoting a numerical quantity but not order
	serving as an essential component