a Not conforming to rule or system; deviating from the usual or normal type. (defdate|First attested around the mid 19th century.)(reference-book | last =| first = | authorlink = | coauthors = | editor =Brown, Lesley | others = | title = The Shorter Oxford English Dictionary | origdate = | origyear = 1933| origmonth = | url = | format = | accessdate = | accessyear = | accessmonth = | edition = 5th | date = | year =2003| month = | publisher =Oxford University Press | location =Oxford, UK | language = | id = | doi = | isbn =978-0-19-860575-7 | lccn = | ol = | pages =6| chapter = | chapterurl = | quote =)
a Of or pertaining to that which is abnormal, in particular, behaviour that deviates from norms of social propriety or accepted standards of mentalhealth. (defdate|First attested around the early 20th century.)