thoroughbred vs grownup

thoroughbred and grownup both are nouns.

Word	Noun	Adjective	Verb	Adverb
thoroughbred	Yes	Yes	No	No
grownup	Yes	Yes	No	No

As nouns, grownup is a hypernym of thoroughbred; that is, grownup is a word with a broader meaning than thoroughbred:

Other hypernyms of thoroughbred include adult.

thoroughbred (noun)	grownup (noun)
a pedigreed animal of unmixed lineage; used especially of horses	a fully developed person from maturity onward
a racehorse belonging to a breed that originated from a cross between Arabian stallions and English mares
a well-bred person

thoroughbred (adjective)	grownup (adjective)
having a list of ancestors as proof of being a purebred animal	(of animals) fully developed