gambler vs doer

gambler and doer both are nouns.

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

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

gambler: a person who wagers money on the outcome of games or sporting events
doer: a person who acts and gets things done

Other hypernyms of gambler include actor, worker.

gambler (noun)	doer (noun)
a person who wagers money on the outcome of games or sporting events	a person who acts and gets things done
someone who risks loss or injury in the hope of gain or excitement