felo-de-se vs killer

felo-de-se and killer both are nouns.

Word	Noun	Adjective	Verb	Adverb
felo-de-se	Yes	No	No	No
killer	Yes	No	No	No

As nouns, killer is a hypernym of felo-de-se; that is, killer is a word with a broader meaning than felo-de-se:

Other hypernyms of felo-de-se include slayer.

felo-de-se (noun)	killer (noun)
an act of deliberate self destruction	predatory black-and-white toothed whale with large dorsal fin; common in cold seas
a person who kills himself intentionally	a difficulty that is hard to deal with
	someone who causes the death of a person or animal
	the causal agent resulting in death