Real Dictionary

mesentery in American English
a supporting membrane or membranes enfolding some internal organ and attaching it either to the body wall or to another organ; esp., a double thickness of the peritoneum enfolding most of the small intestine and attaching it to the spinal wall of the abdo
noun: the membrane, consisting of a double layer of peritoneum, that invests the intestines, attaching them to the posterior wall of the abdomen, maintaining them in position in the abdominal cavity, and supplying them with blood vessels, nerves, and lymphatics

mesentery in British English
noun: the double layer of peritoneum that is attached to the back wall of the abdominal cavity and supports most of the small intestine