Alternation
From BiblePortal Wikipedia
Webster's Dictionary [1]
(1): (n.) Permutation.
(2): (n.) The response of the congregation speaking alternately with the minister.
(3): (n.) The reciprocal succession of things in time or place; the act of following and being followed by turns; alternate succession, performance, or occurrence; as, the alternation of day and night, cold and heat, summer and winter, hope and fear.