"Unusual" or "abnormal" refers to something that deviates from the norm or what is typically expected. This can apply to behaviors, physical characteristics, or occurrences that are not commonly observed. For example, a rare disease may present symptoms that are not typical for most illnesses, making it unusual. In psychology, unusual behaviors might indicate a mental health disorder if they significantly impact a person's daily life. Understanding what is considered unusual helps professionals identify and address various conditions, ensuring individuals receive appropriate support and treatment.