decade
n. countablen. a period of ten years. You use it to talk about a specific block of time, like the 1990s.
n. a period of ten consecutive years. Often used to categorise historical eras or social trends.
The town changed a lot over the last decade.
It took nearly a decade of hard work for the scientist to finish her research project.
The rapid advancement of digital technology over the previous decade has fundamentally altered how we communicate and consume media on a global scale.
From Middle English decade, from Old French decade, from Late Latin decādem (“(set of) ten”), from Ancient Greek δεκάς (dekás), from δέκα (déka, “ten”). In reference to a span of ten years, originally a clipping of the phrase decade of years. By surface analysis, dec- + -ade. Doublet of decad and dekad.
Commonly used with the preposition 'over' or 'during' to describe changes across time.