Merriam-Webster Collegiate Dictionary - deviate

 I. verb  (-ated; -ating)  Etymology: Late Latin deviatus, past participle of deviare, from Latin de- + via way — more at way  Date: circa 1633  intransitive verb  1. to stray especially from a standard, principle, or topic  2. to depart from an established course or norm a flight forced by weather to ~ south  transitive verb to cause to turn out of a previous course  Synonyms: see swerve  • deviator noun  • deviatory adjective  II. noun  Date: 1912  1. one that ~s from a norm; especially a person who differs markedly from a group norm  2. a statistical variable that gives the deviation of another variable from a fixed value (as the mean)  III. adjective  Date: 1929 departing significantly from the behavioral norms of a particular society ~ behavior