The Collaborative International Dictionary of English v.0.48:
Enteron \En"te*ron\, n. [NL., fr. Gr. 'e`nteron an intestine, fr. 'ento`s within.] (Anat.) The whole alimentary, or enteric, canal. [1913 Webster]WordNet (r) 3.0 (2006):
enteron n 1: the alimentary canal (especially of an embryo or a coelenterate)