A pouch-shaped organ that forms part of the digestive tract between the esophagus and the duodenum. It is made of muscle and lined with a mucous membrane that protects it from the acids which it secretes to aid digestion.

Also, the belly or abdomen. Note that the actual stomach is located higher up than the region of the body which is usually called the stomach. Many stomachaches are intestinal, just as heartburn is really a stomach condition.