murderess vs manslayer

murderess and manslayer both are nouns.

Word	Noun	Adjective	Verb	Adverb
murderess	Yes	No	No	No
manslayer	Yes	No	No	No

As nouns, manslayer is a hypernym of murderess; that is, manslayer is a word with a broader meaning than murderess:

murderess: a woman murderer
manslayer: a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)

Other hypernyms of murderess include liquidator, murderer, adult female, woman.

murderess (noun)	manslayer (noun)
a woman murderer	a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)