Mestizo is a term primarily used to denote people of mixed Spanish and Indigenous ancestry in the former Spanish Empire. In certain regions such as Latin America, it may also refer to people who are culturally European, even though their ancestors were Indigenous Americans. The term was used as an ethno-racial exonym for mixed-race castas that evolved during the Spanish Empire. It was a formal label for individuals in official documents, such as censuses, parish registers, Inquisition trials, and others. Priests and royal officials might have classified persons as mestizos, but individuals also used the term in self-identification. With the Bourbon reforms and the independence of the Americas, the caste system disappeared and terms like "mestizo" fell in popularity.
The noun mestizaje, derived from the adjective mestizo, is a term for racial mixing that did not come into usage until the 20th century; it was not a colonial-era term. In the modern era, mestizaje is used by scholars such as Gloria Anzaldúa as a synonym for miscegenation, with positive connotations.