sparer vs benefactor

sparer and benefactor both are nouns.

Word	Noun	Adjective	Verb	Adverb
sparer	Yes	No	No	No
benefactor	Yes	No	No	No

As nouns, benefactor is a hypernym of sparer; that is, benefactor is a word with a broader meaning than sparer:

sparer: someone who refrains from injuring or destroying
benefactor: a person who helps people or institutions (especially with financial help)

Other hypernyms of sparer include helper.

sparer (noun)	benefactor (noun)
someone who refrains from injuring or destroying	a person who helps people or institutions (especially with financial help)