In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life. It is often contrasted with the scientific name for the same organism, which is often based in Latin. Common names can be used frequently, but that is not always the case.
In chemistry, IUPAC defines a common name as one that, although it unambiguously defines a chemical, does not follow the current systematic naming convention, such as acetone, systematically 2-propanone, while a vernacular name describes one used in a lab, trade or industry that does not unambiguously describe a single chemical, such as copper sulfate, which may refer to either copper(I) sulfate or copper(II) sulfate.