Source : Webster's Revised Unabridged Dictionary (1913)

Antiphon \An"ti*phon\, n. [LL. antiphona, fr. Gr. ?. See
   {Anthem}.]
   1. A musical response; alternate singing or chanting. See
      {Antiphony}, and {Antiphone}.

   2. A verse said before and after the psalms. --Shipley.

Source : WordNet®

antiphon
     n : a verse or song to be chanted or sung in response [syn: {antiphony}]