Learn the meaning, pronunciation and examples of the adjective odd , which can describe something strange, unusual, or not matching. Find out how to use odd in idioms, compounds, and expressions. Oppositional Defiant Disorder ( ODD ) is a complex and often misunderstood behavioural disorder that predominantly affects children and adolescents. It is characterized by persistent patterns of defiant, disobedient, and hostile behaviours directed primarily towards authority figures, such as parents, teachers, or caregivers. These behaviours extend beyond typical childhood defiance, affecting a child's social, educational, and family functioning. Early identification and intervention are ... Oppositional defiant disorder ( ODD ) is a behavioral disorder affecting children and teenagers. Learn about its causes, symptoms, and available treatment approaches. The adjective ' odd ' has an etymology that traces back to the Old Norse word 'odda,' which means 'third or additional number.' In Old Norse, 'odda' was used to describe something that was unusual or different because it did not fit the common pairs or even numbers. Over time, this meaning evolved, and the term ' odd ' came to refer to things that were strange, peculiar, or out of the ordinary, deviating from the expected patterns or norms. Therefore, the etymology of ' odd ' reflects its ...