Systole and diastole are two terms used in the medical field to describe the different phases of the cardiac cycle, namely the contraction and relaxation of the heart muscle. However, there are several synonyms that can be used to express the same concept. For example, systole could be referred to as contraction, contraction phase, or ventricular contraction. Similarly, diastole could be described as relaxation, relaxation phase, or ventricular relaxation. These terms are often used interchangeably depending on the context and the level of detail required in a particular discussion. Other related terms include systolic blood pressure and diastolic blood pressure, which are measures of the pressure exerted by the heart during its different phases.