freewheeler vs doer

freewheeler and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
freewheeler	Yes	No	No	No
doer	Yes	No	No	No

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

Other hypernyms of freewheeler include actor, worker.

freewheeler (noun)	doer (noun)
someone acting freely or even irresponsibly	a person who acts and gets things done