Webster's Revised Unabridged Dictionary · 1913

Responsory

Responsory (r?*sp?n"s?*r?) , adjective

Containing or making answer; answering. — Johnson

Responsory (-r{not transcribed}z) , noun

[Late Latin responsorium.]

1.
(a) (Ecclesiastical) The answer of the people to the priest in alternate speaking, in church service.
(b)
(Ecclesiastical) 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.
(Ecclesiastical) An antiphonary; a response book.