abnormality definition
abnormality. 1. the state of being unlike the usual condition. 2. a malformation. inherited abnormality. a defect of anatomy or function acquired by the patient from its parents by way of inherited material passed through the germ cells from which the patient originated.eft atrial abnormality an atrial conduction abnormality accompanied by an enlarged left atrium; on the electrocardiogram it is seen as notched upright P waves in leads I, II, and V4 to V6, and a deep broad terminal trough in V1.