Definition of duodenum in English:



  • The first part of the small intestine immediately beyond the stomach, leading to the jejunum.

    • ‘It is a tube approximately 20 feet long consisting of three regions; the duodenum, jejunum, and ileum.’
    • ‘Multiple biopsies were taken from the duodenum, the gastric antrum, and the distal esophagus.’
    • ‘All this then enters the digestive tract and begins its passage from esophagus to stomach to duodenum to small intestine to colon.’
    • ‘You may have to have part of your stomach, gall bladder and duodenum (the first bit of your small intestine) removed too.’
    • ‘The distal duodenum and duodenal jejunal junction is especially susceptible to damage because it is fixed in position.’


Late Middle English: from medieval Latin, from duodeni ‘in twelves’, its length being equivalent to the breadth of approximately twelve fingers.