A decade is a period of 10 years (since 1594)[1], a factor of 10 difference between two numbers, or sometimes a set or a group of ten (since 1451). It is also a period of 10 days in the French Republican calendar. The word is derived from the late Latin "decas", from Greek "dekas", from deka. The other English words for periods of several years also come from Latin: lustrum (5), century (100), millennium (1000). A year (from Old English gēr) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A decade on a graphical logarithmic scale represents multiplication by 10 from the previous value. ... A French Revolutionary Calendar in the Historical Museum of Lausanne. ... For other uses, see Latins and Latin (disambiguation). ... Lustrum was a sacrifice for expiation and purification offered by one of the censors of Rome in name of the Roman people at the close of the taking of the census, and which took place after a period of five years, so that the name came to denote a period... A century (From the Latin cent, one hundred) is one hundred consecutive years. ... A millennium (pl. ...

In English the word can be used to specify a general period of ten years, for example "The last decade was characterized by the rise of the Internet". A decade may also be a well-def