Communicable disease, also known as infectious disease, is a term used to describe an illness that can be transmitted from one person to another through direct or indirect contact. There are several synonyms for communicable disease, including contagious disease, infectious illness, transmissible disease, and infective disorder. These terms all refer to the same thing: an illness that can be spread from person to person. It's important to note that not all diseases are communicable, as some are caused by non-infectious agents like genetics or environmental factors. However, communicable diseases are a significant global health concern and often require immediate attention to prevent further spread in communities.