gaolbird vs criminal

gaolbird and criminal both are nouns.

Word	Noun	Adjective	Verb	Adverb
gaolbird	Yes	No	No	No
criminal	Yes	Yes	No	No

As nouns, criminal is a hypernym of gaolbird; that is, criminal is a word with a broader meaning than gaolbird:

gaolbird: a criminal who has been jailed repeatedly
criminal: someone who has committed a crime or has been legally convicted of a crime

Other hypernyms of gaolbird include crook, felon, malefactor, outlaw.

gaolbird (noun)	criminal (noun)
a criminal who has been jailed repeatedly	someone who has committed a crime or has been legally convicted of a crime

gaolbird (adjective)	criminal (adjective)
	guilty of crime or serious offense
	involving or being or having the nature of a crime
	bringing or deserving severe rebuke or censure