Latin alternatio: compare with French alternation.
- The reciprocal succession of (normally two) 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.
- The response of the congregation speaking alternately with the minister.
- (linguistics) ablaut
- (logic) The "inclusive or" truth function.
- (mathematics) A sequence that alternates between positive and negative values. (Sometimes wrongly used to mean a permutation.)