[ il-ee-uh m ]
/ ˈɪl i əm /

noun, plural il·e·a [il-ee-uh] /ˈɪl i ə/.

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.


Nearby words

  1. ileosigmoidostomy,
  2. ileostomy,
  3. ileotomy,
  4. ilesha,
  5. iletin,
  6. ileus,
  7. ileus subparta,
  8. ilex,
  9. ilford,
  10. ilhéus

Origin of ileum

1675–85; < New Latin, Medieval Latin īleum, variant of Latin īlia (neuter plural) side of the body between hips and groin, guts, apparently by confusion with Latin īleus ileus

Related formsil·e·al, adjective

Can be confusedileum ilium Ilium Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ileum

British Dictionary definitions for ileum


/ (ˈɪlɪəm) /


the part of the small intestine between the jejunum and the caecum
the corresponding part in insects

Word Origin for ileum

C17: New Latin, from Latin īlium, īleum flank, groin, of obscure origin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History 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.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for ileum


[ ĭlē-əm ]

n. pl. il•e•a (-ē-ə)

The third and terminal portion of the small intestine, extending from the jejunum to the cecum.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for ileum


[ ĭlē-əm ]

Plural ilea

The lower part of the small intestine, connecting the jejunum to the cecum of the large intestine.
Related formsileal adjective

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.