iceman vs liquidator

iceman and liquidator both are nouns.

Word	Noun	Adjective	Verb	Adverb
iceman	Yes	No	No	No
liquidator	Yes	No	No	No

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

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

Other hypernyms of iceman include manslayer, murderer.

iceman (noun)	liquidator (noun)
someone who cuts and delivers ice	(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)