Complainer
Pronunciation : Com*plain"er
Part of Speech : n.
Definition : Defn: One who complains or laments; one who finds fault; a murmurer. Beattie. Speechless complainer, I will learn thy thought. Shak.
Source : Webster's Unabridged Dictionary, 1913
Merriam-Webster's Everyday Language Reference Set: Includes: The Merriam-Webster Dictionary, The Merriam-Webster Thesaurus, and The Merriam-Webster Vocabulary Builder