The Collaborative International Dictionary of English v.0.48:

Antistrophe \An*tis"tro*phe\, n. [L., fr. Gr. ?, fr. ? to turn
   to the opposite side; 'anti` against + ? to turn. See
   Strophe.]
   1. In Greek choruses and dances, the returning of the chorus,
      exactly answering to a previous strophe or movement from
      right to left. Hence: The lines of this part of the choral
      song.
      [1913 Webster]

            It was customary, on some occasions, to dance round
            the altars whilst they sang the sacred hymns, which
            consisted of three stanzas or parts; the first of
            which, called strophe, was sung in turning from east
            to west; the other, named antistrophe, in returning
            from west to east; then they stood before the altar,
            and sang the epode, which was the last part of the
            song.                                 --Abp. Potter.
      [1913 Webster]

   2. (Rhet.)
      (a) The repetition of words in an inverse order; as, the
          master of the servant and the servant of the master.
      (b) The retort or turning of an adversary's plea against
          him.
          [1913 Webster]

WordNet (r) 3.0 (2006):

antistrophe
    n 1: the section of a choral ode answering a previous strophe in
         classical Greek drama; the second of two metrically
         corresponding sections in a poem