ladies' man vs undoer

ladies' man and undoer both are nouns.

Word	Noun	Adjective	Verb	Adverb
ladies' man	Yes	No	No	No
undoer	Yes	No	No	No

As nouns, undoer is a hyponym of ladies' man; that is, undoer is a word with a more specific, narrower meaning than ladies' man:

ladies' man (noun)	undoer (noun)
a man who takes advantage of women	a person who destroys or ruins or lays waste to
	a person who unfastens or unwraps or opens
	a seducer who ruins a woman