ab·dom·i·nal I. \abˈdämənəl, əb-\adjective Etymology: French, from abdomin- + -al 1.: of or belonging to the abdomen : ventral < abdominal muscle > 2.of a fish: having the pelvic or ventral fins under the abdomen and behind the pectoral fins II. noun (-s) : an abdominal element (as a vein or muscle)