Isopiestic is a term used to describe a situation where two or more substances have the same osmotic pressure. Though it is a unique term, there are few synonyms that can be used to define it. Some of these synonyms include isoosmotic, isotonic, isobaric, equiosmotic, and isomolal. These synonyms essentially provide an alternative word to describe the same condition where two substances have an equal pressure, thereby making it easier to convey this meaning to others who may not be familiar with the term isopiestic. Using synonyms for technical terms like isopiestic can make the communication of scientific concepts smoother and easier to understand.