Before diving into the myths, what does odd stand for? It stands for oppositional defiant disorder. Many people find themselves asking, “what is odd?” and “what does odd mean?” Simply put, it is a childhood behavioral problem characterized by a persistent pattern of uncooperative, defiant, and angry behavior toward authority figures. Worried parents sometimes ask, “what is odd disease?”—but it’s important to clarify that it is a mental health and behavioral disorder, not a physical disease.