abnormal

Etymology

From ab- + normal. First attested in 1835, replacing the earlier anormal and even earlier abnormous, from Latin abnormis (“departing from normal”), from either (ab- (“away from”) + norma (“rule, norm”)), or Ancient Greek ἀνώμαλος (anṓmalos).

adj

1. Not conforming to rule or system; deviating from the usual or normal type.
   And then after an abnormal meal, which was either a very late breakfast or a very early lunch, they drove on to Victoria Station. 1899, Arthur Conan Doyle, chapter 6, in A Duet
2. Of or pertaining to that which is irregular, in particular, behaviour that deviates from norms of social propriety or accepted standards of mental health.
   Many of the so-called rites of these secret societies were so patently ridiculous, that it is quite obvious that they were merely an excuse for men and women to indulge in sex-play and lustful gratification, frequently of an abnormal kind. 1936, Rollo Ahmed, The Black Art, London: Long, page 161

noun

1. A person or object that is not normal.