Trigonal is a term used in chemistry to describe a molecule or ion that has a threefold symmetry axis. Synonyms for this word include triangular, triangularly-shaped, three-sided, and three-cornered. These words all describe the same concept of having three sides or angles. In addition to these synonyms, trigonal can also be replaced with the term "triclinic" when describing crystal structures. Understanding these synonyms is essential for students and professionals alike in the fields of chemistry, physics, and crystallography. By having a wide-ranging vocabulary, scientists can accurately and effectively communicate about the molecular and crystalline structures that they study and work with.