baby buster vs doer

baby buster and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
baby buster	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of baby buster; that is, doer is a word with a broader meaning than baby buster:

baby buster: a person born in the generation following the baby boom when the birth rate fell dramatically
doer: a person who acts and gets things done

Other hypernyms of baby buster include actor, worker.

baby buster (noun)	doer (noun)
a person born in the generation following the baby boom when the birth rate fell dramatically	a person who acts and gets things done