'Deviant' definitions:

Definition of 'deviant'

adjective

Markedly different from an accepted norm; "aberrant behavior"; "deviant ideas" [syn: aberrant, deviant, deviate]

noun

A person whose behavior deviates from what is acceptable especially in sexual behavior [syn: pervert, deviant, deviate, degenerate]

From: GCIDE

Deviant \De"vi*ant\, a.
1. Deviating. [Obs.] [1913 Webster]
2. having behavior or characteristics differing from that which is normal or expected, especially in an undesirable or socially disapproved manner; as, deviant behavior.
Syn: deviate. [PJC]