vuosikymmentä

Vuosikymmentä is a Finnish noun meaning a decade, a period of ten years. It is a compound formed from vuosi (year) and kymmenen (ten), and is used to describe a ten-year span in time, whether in historical discussion, age, or duration.

In Finnish, vuosikymmentä is typically used with numerals to express counts of decades, for example kolme vuosikymmentä (three decades) or kaksikymmentä vuosikymmentä (twenty decades). It can also appear in constructions that denote the age or duration of something, such as auto on kaksikymmentä vuosikymmentä vanha (the car is about two decades old) or projekti kesti noin vuosikymmentä (the project lasted around a decade). The singular base form is vuosikymmen, while the common inflected forms include the partitive vuosikymmentä and the plural forms vuosikymmenten (genitive) or vuosikymmenet (nominative).

Vuosikymmenkatto is often used to distinguish a ten-year period within broader timeframes, such as calendar decades (the 1990s) or more loosely defined eras, and it is frequently employed in historical, sociological, or cultural writing to organize events, trends, and developments by ten-year blocks. The concept is distinct from vuosisata, which denotes a century (a hundred years), and from ajanjakso expressions that describe shorter or longer spans.

See also: vuosisata, vuosi, kymmenen vuotta, aikakausi.