small intestine

American  

noun

Anatomy.

1. intestine.

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small intestine British  

noun

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

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small intestine Scientific  

1. 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.

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small intestine Cultural  

1. 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.

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Etymology

Origin of small intestine

First recorded in 1760–70

Example Sentences

The researchers found that these activated T cells gather in the lining of the small intestine, placing them in an ideal position to respond quickly when damage occurs.

From Science Daily • May 21, 2026

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

The trial, led by Ghosh, began in November, and uses electrodes to detect activity of the small intestine.

From BBC • Mar. 11, 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

The tumor in the small intestine is harder to measure.

From "All the Light We Cannot See" by Anthony Doerr