Underbrace is a term that is commonly used in mathematics and computer programming to denote a way of grouping elements in an equation or code. It is often used to indicate that a certain element or group of elements are associated with a particular operation or function. Synonyms for underbrace include bracket, brace, or delimiter. These terms are often used interchangeably and can refer to the same grouping of elements within a mathematical or programming context. Regardless of the exact terminology used, the use of underbrace, bracket, brace, or delimiter is essential in clearly communicating mathematical and programming concepts to others.