Molcajete (pronounced mole-cah-HAY-tay) is a three-legged mortar that’s traditionally used in Mexican cooking.
 
 
(Oxford English Dictionary)
molcajete, n.
[< Mexican Spanish molcajete (1827) < Nahuatl

mo:lcaxitl.] 
A mortar, usually made of stone or clay, used in Mexican cooking for pounding spices.
1906 M. E. SOUTHWORTH 101 Mexican Dishes 13 Soak five chiles in hot water.., wash them well and put in a mortar (the Mexicans use the molcajete and tejolote). 1929 Jrnl. Amer. Folk-lore 42 174 Chili peppers, and other condiments are ground with the stone mortar and pestle, the molcajete (molcaxitl) and tejolote (texolotl). 1969 Sunset Mexican Cook Bk. 6/2 To grind chiles, herbs, nuts, and chocolate, she may use a smaller, three-legged mortar of stone called molcajete.
 
23 October 1980, Chicago Tribune, pg. WB1:
Pronounced mole-cah-HAY-tay, this rough stone utensil works like a mortar and pestle, blending spices and releasing their flavor into pastelike seasoning mixtures important for simple and elegant dishes. The one pictured here is of a dark, porous stone; its rough surface is perfect for mashing and grinding spices, herbs, and vegetables. it must first be scoured with a stiff brush and water. Then, one handful of rice ground at a time, washing the utensil between batches. When the rice stays white instead of gray the molcajete is ready to use. Price: 6.59.