slanderer vs maligner

slanderer and maligner both are nouns.

Word	Noun	Adjective	Verb	Adverb
slanderer	Yes	No	No	No
maligner	Yes	No	No	No

As nouns, slanderer and maligner are synonyms defined as:

slanderer and maligner: one who attacks the reputation of another by slander or libel

Other synonyms of slanderer include backbiter, defamer, libeler, traducer, vilifier.

slanderer (noun)	maligner (noun)
one who attacks the reputation of another by slander or libel	one who attacks the reputation of another by slander or libel