Mid'riff, n.

n. [A-S. midhrif, from midd, mid, middle, and hrif, bowels, womb; O. Fries. midref.] (Anat.) The diaphragm; the respiratory muscle which divides the trunk into two cavities, the thorax and abdomen. “A sight to shake the midriff of Despair with laughter.” Tennyson.

Smote him into the midriff with a stone. Shak.