the last portion of the vertebrate alimentary canal, between the cecum and the anus, involved mainly with water resorption and with the storage and elimination of food residue; the large intestine.
b.
the posterior colon of arthropods, composed of ectodermal, chitin-lined tissue.
2.
Embryology,Zoology. the posterior part of the embryonic alimentary canal from which the colon and rectum develop.