Responsorial(a.) Responsory; antiphonal.
Responsory(a.) Containing or making answer; answering.
Responsory(n.) The answer of the people to the priest in alternate speaking, in church service.
Responsory(n.) A versicle sung in answer to the priest, or as a refrain.
Responsory(n.) An antiphonary; a response book.

Words within responsories