libeler vs vilifier

libeler and vilifier both are nouns.

Word	Noun	Adjective	Verb	Adverb
libeler	Yes	No	No	No
vilifier	Yes	No	No	No

As nouns, libeler and vilifier are synonyms defined as:

libeler and vilifier: one who attacks the reputation of another by slander or libel

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

libeler (noun)	vilifier (noun)
one who attacks the reputation of another by slander or libel	one who attacks the reputation of another by slander or libel