- Zoology.
- the middle portion of the vertebrate alimentary canal, posterior to the stomach or gizzard and extending to the cecum, functioning in the digestion and absorption of food; the small intestine.
- the anterior portion of the arthropod colon, composed of endodermal tissue.
- the middle part of the embryonic alimentary canal from which the intestines develop.
- the middle part of the digestive tract of vertebrates, including the small intestine
- the middle part of the digestive tract of arthropods
