A pleuropericardial murmur refers to an abnormal sound that occurs when the lining of the lungs (pleura) and the sac surrounding the heart (pericardium) rub against each other due to inflammation or other underlying conditions. Although "pleuropericardial murmur" is the commonly used medical term, there are other synonyms to describe this condition. Some of the alternative phrases that can be used to refer to a pleuropericardial murmur include pleural friction rub, pericardial friction rub, and chest wall rubbing sound. These terms all describe the same phenomenon of abnormal sounds occurring in the pleura and pericardial regions, providing options for physicians and researchers to refer to this condition interchangeably.