- Anatomy. the third and lowest division of the small intestine, extending from the jejunum to the cecum.
- Zoology. the anterior portion of the hindgut of an insect or other arthropod.
Origin of ileum
- Inner London Education Authority
- the part of the small intestine between the jejunum and the caecum
- the corresponding part in insects
Word Origin for ileum
lowest part of the small intestine, 1680s, medical Latin, from ileum, singular created from classical Latin plural ilia "groin, flank," in classical Latin, "belly, the abdomen below the ribs," poetically, "entrails, guts." Sense restriction and form apparently from confusion with Greek eileos (see ileus). Earlier in English ylioun (late 14c.), from Medieval Latin ileon. Related: Ileitis.
- The third and terminal portion of the small intestine, extending from the jejunum to the cecum.
- The lower part of the small intestine, connecting the jejunum to the cecum of the large intestine.