אִסְתֹּומְכָא, (Ithpe. noun of סמך; cmp. סוּמְכָא) the thick part, or the protection of an organ of the body, muscle, cartilage &c. Ḥull. 50ᵇ (explaining ‘the inner stomach’) א׳ דכרסא (Ar. אסט׳) the thick portion of the rumen (?). Ab. Zar. 29ᵃ א׳ דליבא the protector of the heart (or of the stomach), the cartilago ensiformis, xiphoides, v. אוּנְקְלַי I, 3; (other opinion rejected in Rashi: fleshy walls of the heart).