The Collaborative International Dictionary of English v.0.48:

Eurythmy \Eu"ryth*my\, n. [L. eurythmia, Gr. ?; e'y^ well + ?
   rhythm, measure, proportion, symmetry: cf. F. eurythmie.]
   1. (Fine Arts) Just or harmonious proportion or movement, as
      in the composition of a poem, an edifice, a painting, or a
      statue.
      [1913 Webster]

   2. (Med.) Regularly of the pulse.
      [1913 Webster]

WordNet (r) 3.0 (2006):

eurythmy
    n 1: the interpretation in harmonious bodily movements of the
         rhythm of musical compositions; used to teach musical
         understanding [syn: eurythmy, eurhythmy, eurythmics,
         eurhythmics]