1. An unexpected rush or an overwhelming outpouring of something: The spate of world explorations, that started in the 1400s and the wealth of knowledge which was amassed, changed geography as a science.
2. Situations in which people encounter an unexpected and excessive supply of something: When there are too many books, robberies, celebrity break-ups, or corporate mergers; obviously all kinds of spates are going on.
3.Etymology: although it is now used to describe a large number or an unusually large amount of something, it originally described a sudden flood of water; such as, a river overflowing after a strong downpour of rain.