Synonyms

small intestine

American

noun

Anatomy.

intestine.

small intestine British

noun

the longest part of the alimentary canal, consisting of the duodenum, jejunum, and ileum, in which digestion is completed Compare large intestine

"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

small intestine Scientific

The long, narrow, coiled section of the intestine that extends from the stomach to the beginning of the large intestine. Nutrients from food are absorbed into the bloodstream from the small intestine. In mammals, it is made up of the duodenum, jejunum, and ileum.

small intestine Cultural

The upper portion of the intestines, extending from the stomach to the large intestine, where the digestion of food takes place. The small intestine is about twenty feet long in adults.

Etymology

Origin of small intestine

First recorded in 1760–70

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Duodenal mucosal resurfacing is an investigational endoscopic treatment that uses controlled heat to remove damaged tissue from the inner lining of the duodenum, the first section of the small intestine just below the stomach.

From Science Daily • Apr. 23, 2026

Their approach uses a cyclic peptide that can pass through the small intestine, known as the DNP peptide.

From Science Daily • Mar. 24, 2026

Only part of the sugar is absorbed in the small intestine, while much of it is fermented by gut bacteria in the colon.

From Science Daily • Jan. 13, 2026

But that all changed in 2024 when she received a "game-changing diagnosis" of coeliac disease, an autoimmune condition whereby consuming gluten causes the body's immune system to attack internal organs, including the small intestine.

From BBC • Dec. 10, 2025

There she found a ring of bleeding spots at the junction between the stomach and the small intestine.

From "The Hot Zone" by Richard Preston

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023