Deviant means departing sharply from what is accepted as normal. Deviant behaviour, socially deviant, a deviant case.
In sociology it is neutral and technical: deviance is anything a society treats as outside its norms, which changes with the society. In ordinary speech it is heavily loaded and usually sexual, and it has been used to condemn a great deal that harmed nobody.
1adjectivedeviantDeparting sharply from what is accepted as normal.
“The police psychologist studied the deviant behaviour of repeat offenders.”
deviant is a quality.
DEVIant → it DIVIDEs off from the rest
One sheep leaves the flock and goes the other way. The road divides and it takes the side that nobody uses.
hooks ontodivide
Latin deviare means to turn from the road — de plus via, a way. Deviate is the same verb.
Latin
dēviāns
Middle English
devyaunt — deviating, different
English, today
deviant
Built from
From Middle English devyaunt (“deviating, different”), from Latin dēviāns, present participle of dēviō (“to stray, deviate or detour”). The noun is from the adjective, possibly attested in Middle English with the meaning “one who goes astray”.
Etymology from Wiktionary, CC BY-SA