||Mes*en"te*ron (?), n. [NL. See Meso-, and Enteron.] (Anat.) All that part of the alimentary canal which is developed from the primitive enteron and is lined with hypoblast. It is distinguished from the stomodæum, a part at the anterior end of the canal, including the cavity of the mouth, and the proctodæum, a part at the posterior end, which are formed by invagination and are lined with epiblast.