a word created through misreading of manuscripts, misunderstanding of grammatical elements, etc. and never really established in a language
Origin:
term invented by W. W. W(alter) W(illiam) Skeat
See ghost word in American Heritage Dictionary 4
noun
A word that has come into a dictionary, grammar, or other scholarly work as a result of a misreading or misinterpretation, as by mistaking a typographical error for an actual word.