The Collaborative International Dictionary of English v.0.48:

oesophagus \oe*soph"a*gus\, n., oesophageal \oe`so*phag"e*al\,
   a., etc.
   Same as Esophagus, Esophageal, etc.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Esophagus \E*soph"a*gus\, n. [NL., fr. Gr. o'isofa`gos; root of
   o'i`sw which is used as future of fe`rein to bear, carry (cf.
   Skr. v[imac] to go, drive) + fagei^n to eat.] (Anat.)
   That part of the alimentary canal between the pharynx and the
   stomach; the gullet. See Illust. of Digestive apparatus,
   under Digestive. [Written also [oe]sophagus.] Esopian

WordNet (r) 3.0 (2006):

oesophagus
    n 1: the passage between the pharynx and the stomach [syn:
         esophagus, oesophagus, gorge, gullet]