Quadroon, and the associated words octoroon and quintroon are terms that, historically, were applied to define the ancestry of people of mixed-race, generally of African and Caucasian ancestry, but also, within Australia, to those of Aboriginal and Caucasian ancestry. The terms were used in law and government to provide a precise code of discrimination and the determination of rights. The use of such terminology is a characteristic of hypodescent, which is the practice within a society of assigning children of mixed union to the ethnic group which is perceived by the dominant group as being subordinate. The racial designations refer specifically to the number of full-blooded African ancestors, emphasizing the quantitative least, with quadroon signifying that a person has one-quarter black ancestry, etc.
The word "quadroon" was borrowed from the Spanish cuarterón which has its roots in the Latin quartus, which means fourth. The word octoroon is based on quadroon, and rooted in the Latin octo, which means eight.
Quadroon was used to designate a person of one-quarter African/Aboriginal ancestry, that is one biracial parent (African/Aboriginal and Caucasian) and one Caucasian parent; in other words, one African/Aboriginal grandparent and three Caucasian grandparents.
The term mulatto was used to designate a person who was biracial, with one black parent and one white parent.
The term octoroon referred to a person with one-eighth African ancestry;[that is, someone with family heritage of one biracial grandparent, in other words, one African great-grandparent and seven Caucasian great-grandparents. As with the use of quadroon, this word was applied to a limited extent in Australia for those of one-eighth Aboriginal ancestry, in the putting in place of government assimilation policies.
Terceron was a term synonymous with octoroon, derived from being three generations of descent from an African ancestor (great-grandparent).
The term mustee was also used to refer to a person with one-eighth African ancestry, while mustefino refers to a person with one-sixteenth African ancestry.
The terms "quintroon" or "hexadecaroon" were also applied.
The term Zambo or Cafuzo or Griffe or Sambo has been used for someone of three-quarters African heritage, or the child of a biracial parent and a fully black parent.