Quadroon
Quadroon, and the associated words quarteron, octoroon and quintroon are terms that, historically, were applied to define the ancestry of people of mixed-race, generally of African and European ancestry in the slave societies of the Americas, but also, within Australia, to those of Aboriginal and European ancestry.
Governments incorporated the terms in law defining rights and restrictions. The use of such terminology is a characteristic of hypodescent, which is the practice within a society of assigning children of mixed unions 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 or equivalent, emphasizing the quantitative least, with quadroon signifying that a person has one-quarter black ancestry, etc.
Etymology
The word "quadroon" was borrowed from the French quarteron, and Spanish cuarterón, which have their roots in the Latin quartus, meaning to have a fourth or a "quarter" (25%) of something. The word octoroon is rooted in the Greek octo, which means eight.