Source : Webster's Revised Unabridged Dictionary (1913)

Hindgut \Hind"gut`\, n. [Hind, a. + gut.] (Anat.)
   The posterior part of the alimentary canal, including the
   rectum, and sometimes the large intestine also.

Source : WordNet®

hindgut
     n : the caudal part of the alimentary canal in vertebrate
         embryos