Decade

Noun

1. A group, set, or series of ten .mw-parser-output .defdate{font-size:smaller}, particularly:

   "a decade of soldiers"

2. A period of ten years , particularly such a period beginning with a year ending in 0 and ending with a year ending in 9.

   "The 1960s was a turbulent decade."

3. A period of ten days, particularly those in the ancient Egyptian, Coptic, and French Revolutionary calendars.
4. A work in ten parts or books, particularly such divisions of Livy's History of Rome.
5. A series of prayers counted on a rosary, typically consisting of an Our Father, followed by ten Hail Marys, and concluding with a Glory Be and sometimes the Fatima Prayer.