charmer vs heartbreaker

charmer and heartbreaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
charmer	Yes	No	No	No
heartbreaker	Yes	No	No	No

As nouns, heartbreaker is a hyponym of charmer; that is, heartbreaker is a word with a more specific, narrower meaning than charmer:

charmer: a person who charms others (usually by personal attractiveness)
heartbreaker: a charming person who is irresponsible in emotional relationships

charmer (noun)	heartbreaker (noun)
a person who charms others (usually by personal attractiveness)	a narrow defeat or a defeat at the last minute
someone with an assured and ingratiating manner	a charming person who is irresponsible in emotional relationships