A scorner; an impostor.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
One who mocks; a scoffer; a deceiver.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)

Usage examples:

An expatriated Irishman, a dispossessed landlord, a man without one high ambition, a mere mocker of enthusiasm of every kind.
- Gossamer 1915 by George A. Birmingham
Now Mistah Mocker reached the Green Meadows just after Peter Rabbit had brought little Mrs. Peter down from the Old Pasture to live with him in the dear Old Briar- patch.
- Mrs. Peter Rabbit by Thornton W. Burgess
Ian, the Judas of friendship- thief of a comrade's bliss- cheat, murderer, mocker and injurer!
- Foes by Mary Johnston