Webster's Revised Unabridged Dictionary · 1913

Deviate

Deviate , intransitive verb

[Latin deviare to deviate; de + viare to go, travel, via way. See Viaduct.]

To go out of the way; to turn aside from a course or a method; to stray or go astray; to err; to digress; to diverge; to vary.
Thus Pegasus, a nearer way to take, May boldly deviate from the common track. — Pope

Deviate , transitive verb

To cause to deviate. [Rare]
To deviate a needle. — J. D. Forbes

deviate (dē"ve*it) , adjective

having behavior differing from that which is normal or expected, especially in an undesirable or socially disapproved manner; as, deviate behavior.

deviate (dē"ve*it) , noun

a person having behavior differing from that which is normal or socially acceptable; -- used especially to characterize persons whose sexual behavior is considered morally unacceptable.