(Thesaurus terminology) One of the major divisions of a thesaurus.

The total set of subdivisions within a single class derived form the same principle of division, e.g. parts of the body within Anatomy or Nation states within Politics.

Any of the various categories into which a given class may be divided, e.g., division of the class "people" into the categories of ethnicity, age, education and language spoken. Each category contains terms based on a single characteristic of division, e.g., children, adolescents and adults are characteristics of division of the "ages" category. See also Citation order.

A mutually exclusive category of information in a hierarchy. The AAT has seven facets.

Any of the various categories into which a given class may be divided, e.g., division of the class "people" by the categories race, age, education, language spoken, and so on.