misspelling n 1: a spelling that is incorrect
Misspell \Mis*spell"\, v. t. [imp. & p. p. {Misspelled}, or {Misspelt}; p. pr. & vb. n. {Misspelling}.] To spell incorrectly. [1913 Webster]
Misspelling \Mis*spell"ing\, n. A wrong spelling. [1913 Webster]