A gizzard is a specialized muscular stomach found in birds and some other animals that grinds up food. Since birds don't have teeth, they need another way to break down tough seeds, grains, and other food. The gizzard does this job by contracting its thick, powerful muscles to crush and pulverize everything the bird swallows.

Many birds swallow small stones or grit that collect in their gizzards. These stones act like millstones in an old-fashioned grain mill, helping grind food into smaller pieces that the bird can digest. A chicken's gizzard might contain tiny pebbles that tumble around inside, mashing up corn kernels and seeds.

When people eat chicken, turkey, or duck, the gizzard is one of the organs sometimes included in what's called the giblets, the edible internal organs that come with a whole bird. The gizzard is chewy and has a distinctive texture because it's almost pure muscle. In some cuisines, gizzards are considered a delicacy, though many modern cooks simply discard them or use them to make gravy.

The word can also be used playfully. If something really bothers you, you might say it “sticks in your gizzard,” meaning it's hard to accept or digest, like tough food that won't go down easily.