WordWeb Online

1. Not in accordance with or determined by nature; contrary to nature
   "an unnatural death"; "the child's unnatural interest in death"
    
2. Not normal; not typical, usual, regular or conforming to a norm
   "unnatural powers of concentration";
   - abnormal
    
3. Speaking or behaving in an artificial way to make an impression
   - affected

See also: aberrant, affected, affectedness, agonistic, anomalous, antidromic, artificial, atypical, brachydactylic, brachydactylous, constrained, contrived, defective, deviant, deviate, effeteness, elocutionary, forced, freakish, hokey [N. Amer, informal], insane, irregular, kinky [informal], mannered, naturalness, normalcy [N. Amer], normality, paranormal, perverted, plummy, poncey [Brit, informal], poncy [Brit, informal], stilted, strained, studied, subnormal, supernatural, supernormal, vicarious, violent

Antonym: natural, normal

Encyclopedia: Unnatural