Why turkey has the same name as Turkey
"stomach of a bird," late 14c., from Old French gisier (Modern French gésier) "entrails, giblets (of a bird)," probably from Vulgar Latin *gicerium, dissimilated from Latin gigeria (neuter plural) "cooked entrails of a fowl," a delicacy in ancient Rome, from PIE *yekwr- "liver" (see hepatitis). Parasitic -d added 1500s. Later extended to other animals, and, jocularly, to human beings.
in many birds, the hind part of the stomach, especially modified for grinding food. Located between the saclike crop and the intestine, the gizzard has a thick muscular wall and may contain small stones, or gastroliths, that function in the mechanical breakdown of seeds and other foods. In this sense, the gizzard is comparable to the teeth of other animals. A few other animals, such as earthworms and some moss animals, also have gizzardlike structures.