A prediastolic murmur is a medical term used to describe an abnormal sound heard during the relaxation phase of the heart's cycle, which occurs just before the heart muscle begins to contract. While there are no direct synonyms for this term, it can be described as a late diastolic murmur. The term "late diastolic murmur" is often used interchangeably with "prediastolic murmur" as they both refer to abnormal heart sounds heard during the same phase of the cardiac cycle. It is important to note that both terms are used by medical professionals to describe similar conditions and should be understood in the same context.