Origin and Etymology of ileum
New Latin, alteration of Latin ilia, plural, groin, viscera
First Known Use: 1682
Medical Definition of ileum
: the last division of the small intestine that constitutes the part between the jejunum and large intestine and in humans forms the last three fifths of the part of the small intestine beyond the end of the duodenum and that is smaller and thinner-walled than the jejunum with fewer circular folds but more numerous Peyer's patches
Seen and Heard
What made you want to look up ileum? Please tell us where you read or heard it (including the quote, if possible).