Wordnet 3.0
NOUN (1)
1. 
 tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; 
 functions in digestion and elimination; 
[syn: alimentary canal, alimentary tract, digestive tube, digestive tract, gastrointestinal tract, GI tract]
WordNet (r) 3.0 (2006):
digestive tract
    n 1: tubular passage of mucous membrane and muscle extending
         about 8.3 meters from mouth to anus; functions in digestion
         and elimination [syn: alimentary canal, alimentary
         tract, digestive tube, digestive tract,
         gastrointestinal tract, GI tract]