Decennia are periods of ten years that are significant in various fields. There are a few different synonyms for this word, which can be helpful to know in order to diversify one's vocabulary. One such synonym is "decade," which is commonly used in everyday language and refers to the same block of time. Another synonym is "ten-year span," which is a more technical term commonly used in research or academic writing. The word "decennial" can also be used to describe anything related to a decennia, such as a decennial celebration or report. Finally, some may use "decennium" as another synonym, although this term is less common in modern usage.