Il"e*um (?), n. [L. ile, ileum, ilium, pl. ilia, groin, flank.]
The last, and usually the longest, division of the small intestine; the part between the jejunum and large intestine.
[Written also ileon
, and ilium
⇒ Most modern writers restrict ileum to the division of the intestine and ilium to the pelvic bone.
© Webster 1913.