Real Dictionary

deviate
verb: To deviate from something means to start doing something different or not planned, especially in a way that causes problems for others.

deviate in American English
a deviant; esp., one whose sexual behavior is deviant
deviant
to cause to deviate
to turn aside (from a course, direction, standard, doctrine, etc.); diverge; digress
adjective: characterized by deviation or departure from an accepted norm or standard, as of behavior
intransitive verb: to turn aside, as from a route, way, course, etc.
noun: a person or thing that departs from the accepted norm or standard
transitive verb: to cause to swerve; turn aside

deviate in British English
verb: to differ or diverge or cause to differ or diverge, as in belief or thought