Gallstones

Definition of gallstone

gallstone

(GAWL-stone)
Solid material that forms in the gallbladder or common bile duct. Gallstones are made of cholesterol or other substances found in the gallbladder. They may occur as one large stone or as many small ones, and vary from the size of a golf ball to a grain of sand. Also called cholelith.

Source: NCI Dictionary of Cancer Terms