The Oxford Thesaurus An A-Z Dictionary of Synonyms - misstep n.

1) false step, blunder, mistake, error, bad or wrong or false move, trip, stumble, slip: One misstep meant a fall into the abyss. 2) indiscretion, mistake, lapse, faux pas, oversight, error, gaffe, Colloq slip-up, Slang howler, Brit bloomer, US and Canadian blooper, goof: Her misstep was telling her fianc‚'s mother that she had formerly been an artist's model.