| Noun | 1. | congenital heart defect - a birth defect involving the heart birth defect, congenital abnormality, congenital anomaly, congenital defect, congenital disorder - a defect that is present at birth septal defect - a congenital abnormality in the septum between the left and right sides of the heart Fallot's syndrome, Fallot's tetralogy, tetralogy of Fallot - a congenital heart defect producing cyanosis; characterized by four symptoms: pulmonary stenosis and ventricular septal defect and malposition of the aorta over both ventricles and hypertrophy of the right ventricle |