Jejunum

from WordNet (r) 3.0 (2006)

jejunum
    n 1: the part of the small intestine between the duodenum and
         the ileum

from The Collaborative International Dictionary of English v.0.48

Jejunum \Je*ju"num\, n. [NL., fr. L. jejunus empty, dry.]
   (Anat.)
   The middle division of the small intestine, between the
   duodenum and ileum; -- so called because usually found empty
   after death.
   [1913 Webster]