The Collaborative International Dictionary of English v.0.48:

Epigastric \Ep`i*gas"tric\, a. [Gr. ? over the belly; 'epi` upon
   + ? belly: cf. F. ['e]pigastrique.]
   1. (Anat.) Pertaining to the epigastrium, or to the
      epigastric region.
      [1913 Webster]

   2. (Zo["o]l.) Over the stomach; -- applied to two of the
      areas of the carapace of crabs.
      [1913 Webster]

   Epigastric region. (Anat.)
      (a) The whole upper part of the abdomen.
      (b) An arbitrary division of the abdomen above the
          umbilical and between the two hypochondriac regions.
          [1913 Webster]

WordNet (r) 3.0 (2006):

epigastric
    adj 1: of or relating to the anterior walls of the abdomen;
           "epigastric artery"
    2: lying on or over the stomach