The Collaborative International Dictionary
metate \me*ta"te\ (m[asl]*t[aum]"t[asl]), n. [Sp., fr. Mex. metlatl.] A flat or somewhat hollowed stone upon which grain or other food is ground, by means of a smaller stone or pestle.
Wiktionary
n. A flat stone with a slightly concave surface, used with another stone (a mano) for grinding maize or other grains.
Wikipedia
A metate or metlatl (or mealing stone) is a type or variety of quern, a ground stone tool used for processing grain and seeds. In traditional Mesoamerican culture, metates were typically used by women who would grind lime-treated maize and other organic materials during food preparation (e.g., making tortillas). Similar artifacts are found all over the world, including China.
Usage examples of "metate".
The first of the latter shows the use of a discarded metate, or mealing stone, and the second of a gourd that has been walled into the coping.
Longarm said, ushering Miranda inside to see displays of pottery and stone relics, including ax heads and metates used for grinding corn.