Ductus arteriosus, commonly known as DA, is a fetal blood vessel that connects the pulmonary artery to the aorta. During the fetal stage, the DA is necessary for circulation to take place since the lungs are not yet functioning. However, after birth, the DA typically closes and is no longer needed. There are several synonyms for the term ductus arteriosus, including the following: arterial duct, Botalli's duct, ductus arteriosum, or ductus Botalli. These terms are often used interchangeably, and medical professionals may use different terms depending on their field of expertise. Understanding these synonyms can be helpful for both medical professionals and individuals seeking to better understand fetal development and circulatory systems.