Pronunciation: (mes'un-ter"ē, mez'-), [key]
—pl. -ter•ies. Anat.
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, esp. the part of this membrane investing the jejunum and ileum.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.