Source : Webster's Revised Unabridged Dictionary (1913)

Responsory \Re*spon"so*ry\ (r?*sp?n"s?*r?), a.
   Containing or making answer; answering. --Johnson.

Responsory \Re*spon"so*ry\, n.; pl. {-ries} (-r?z). [LL.
   responsorium.]
   1. (Eccl.)
      (a) The answer of the people to the priest in alternate
          speaking, in church service.
      (b) A versicle sung in answer to the priest, or as a
          refrain.

                Which, if should repeat again, would turn my
                answers into responsories, and beget another
                liturgy.                          --Milton.

   2. (Eccl.) An antiphonary; a response book.