Midriff (m&ibreve_;dr&ibreve_;f), n. [AS. midhrif; midd mid, middle + hrif bowels, womb; akin to OFries. midref midriff, rif, ref, belly, OHG. href body, and to L. corpus body. See Corpse.] (Anat.) 1. See Diaphragm, n., 2.
[1913 Webster]

2. The middle part of the front of the body, from the waist to the chest.
[PJC]

Smote him into the midriff with a stone. Milton.
[1913 Webster]

3. That part of a garment, especially a dress or bodice, that covers the midriff{2}.
[PJC]