whizz-kid vs doer

whizz-kid and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
whizz-kid	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of whizz-kid; that is, doer is a word with a broader meaning than whizz-kid:

Other hypernyms of whizz-kid include actor, worker.

whizz-kid (noun)	doer (noun)
someone whose career progresses rapidly	a person who acts and gets things done