The Collaborative International Dictionary of English v.0.48:

Homeopathy \Ho*me*op"a*thy\, n. [Gr. ? likeness of condition or
   feeling; ? like (fr. ? same; cf. Same) + ? to suffer: cf.
   F. hom['e]opathie. See Pathos.] (Med.)
   The art of curing, founded on resemblances; the theory and
   its practice that disease is cured (tuto, cito, et jucunde)
   by remedies which produce on a healthy person effects similar
   to the symptoms of the complaint under which the patient
   suffers, the remedies being usually administered in minute
   doses. This system was founded by Dr. Samuel Hahnemann, and
   is opposed to allopathy, or heteropathy. [Written also
   hom[oe]opathy.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

homeopathy
    n 1: a method of treating disease with small amounts of remedies
         that, in large amounts in healthy people, produce symptoms
         similar to those being treated [syn: homeopathy,
         homoeopathy] [ant: allopathy]