gun for hire vs liquidator

gun for hire and liquidator both are nouns.

Word	Noun	Adjective	Verb	Adverb
gun for hire	Yes	No	No	No
liquidator	Yes	No	No	No

As nouns, liquidator is a hypernym of gun for hire; that is, liquidator is a word with a broader meaning than gun for hire:

gun for hire: a professional killer who uses a gun
liquidator: a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)

Other hypernyms of gun for hire include manslayer, murderer.

gun for hire (noun)	liquidator (noun)
a professional killer who uses a gun	(law) a person (usually appointed by a court of law) who liquidates assets or preserves them for the benefit of affected parties
	a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)