%ileum%

‖n. [ L. ile, ileum, ilium, pl. ilia, groin, flank. ] 1. (Anat.) The last, and usually the longest, division of the small intestine; the part between the jejunum and large intestine. [ Written also ileon, and ilium. ] [ 1913 Webster ]

2. (Anat.) See Ilium. [ R. ] [ 1913 Webster ]

☞ Most modern writers restrict ileum to the division of the intestine and ilium to the pelvic bone. [ 1913 Webster ]