The word "decade" refers to a period of ten years. It is commonly used to mark significant time intervals, such as decades in history, music, culture, and personal milestones. For example, the 1980s, or the decade of the 2000s, are often referenced to describe trends, events, or societal changes that took place during those ten years.
The term "decade" comes from the Greek word "dekas," which means "ten." It was adopted into Latin as "decas," from which the English "decade" is derived.