According to the Oxford dictionary, "ghost words" are words that are "recorded in a dictionary or other reference work which is not actually used." Lexicographer Walter Skeat first used the phrase "ghost word" in 1886 to describe words that had "no real existence." They don't really have any meaning and originate from typos, misreading manuscripts, and transcription errors. Examples of ghost words include tweed, dord, morse, esquivalience, and phantomnation.