hatchet man vs liquidator

hatchet man and liquidator both are nouns.

Word	Noun	Adjective	Verb	Adverb
hatchet man	Yes	No	No	No
liquidator	Yes	No	No	No

As nouns, liquidator is a hypernym of hatchet man; that is, liquidator is a word with a broader meaning than hatchet man:

hatchet man: a professional killer
liquidator: a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)

Other hypernyms of hatchet man include manslayer, murderer.

hatchet man (noun)	liquidator (noun)
one whose job it is to execute unpleasant tasks for a superior	(law) a person (usually appointed by a court of law) who liquidates assets or preserves them for the benefit of affected parties
a professional killer	a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)