Dictionary.com's Word of the Year is...
midgut mid·gut (mĭd'gŭt')
The middle section of the digestive tract in a vertebrate embryo from which the ileum, jejunum, and portions of the duodenum and colon develop. Also called mesenteron.
The middle portion of the digestive tract of certain invertebrates, such as arthropods, that is lined with an enzyme-secreting tissue and that serves as the main site of digestion and absorption.