antiphonal

1. Relating to or resembling an antiphon.
2. Answering responsively, as in antiphony.
3. Occurring or responding in turns; alternating: "this curious antiphonal relationship between the two men" (Henry A. Kissinger).

Term describing works, or the manner of performing them (‘in antiphony’), in which an ensemble is divided into two or more distinct groups, performing in alternation and together; hence ‘antiphonal singing’, ‘antiphonal psalmody’ (see Antiphon; Cori spezzati). The term is sometimes used synonymously with ‘antiphoner’, a Liturgical book containing antiphons (see Liturgical books).

The noun has one meaning:

Meaning #1: bound collection of antiphons
  Synonym: antiphonary

The adjective antiphonal has 2 meanings:

Meaning #1: (religion) containing or using responses or antiphons recited or sung in alternation
  Synonym: responsive
  Pertains to noun: antiphon (meaning #1)

Meaning #2: relating to or resembling an antiphon
  Synonym: antiphonary
  Pertains to noun: antiphon (meaning #1)