How do you spell Alternation

Available Definitions:
1)  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.
2)  n. - Permutation.
3)  n. - The response of the congregation speaking alternately with the minister.