Definition of potato clay in US English:

potato clay

noun

  • A variety of clay traditionally used by Hopi Indians (frequently mixed with water) to neutralize bitterness, acidity, or toxins in foods such as wild potatoes, and sometimes in the production of pigments.

Origin

Late 19th century; earliest use found in American Anthropologist. After Hopi tɨm?ncöqa from t?mna potato + c?qa moist earth, mud.