The Collaborative International Dictionary of English v.0.48:

Hippocratic \Hip"po*crat"ic\, a.
   Of or pertaining to Hippocrates, or to his teachings.
   [1913 Webster]

   Hippocratic face [L. facies Hippocratica], the change
      produced in the countenance by death, or long sickness,
      excessive evacuations, excessive hunger, and the like. The
      nose is pinched, the eyes are sunk, the temples hollow,
      the ears cold and retracted, the skin of the forehead
      tense and dry, the complexion livid, the lips pendent,
      relaxed, and cold; -- so called, as having been described
      by Hippocrates. --Dunglison.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Hippocratic
    adj 1: of or relating to Hippocrates or the school of medicine
           that took his name