n. The upper and median part of the abdomen, especially of its surface, or that part lying over the stomach; the epigastric region, commonly called the pit of the stomach.n. In entomology, a term used by some of the older entomologists for the lower side of the mesothorax and metathorax in the Coleoptera, Hemiptera, and Orthoptera.n. Also, sometimes, epigastræum.