Lactide is a cyclic di-ester that is derived from lactic acid, which is widely used in the food, medical, and pharmaceutical industries. It is primarily used as a building block for the production of polylactic acid, a biodegradable polymer with numerous applications. Lactide is also known by several other synonyms, including Lactic anhydride, α-hydroxypropionic acid, and 2-hydroxypropanoic acid cyclic ester. Apart from these chemical terms, it can also be referred to as PLA lactide, polymer-grade lactide, and cyclic dimer of lactic acid. Understanding the various synonyms of lactide is useful when conducting research, selecting materials, and communicating technical information.