a century = 100 years
a millenium = 1000 years
10 years is a decade and 100 years is a century
A decade is a period of 10 years. The word is derived (via French) from the Ancient Greek dekas which means ten. This etymology is sometime confused with the Latin decas (ten) and dies (days), which is not correct. The other words for spans of years come from Latin: lustrum (5 years), century (100 years), millennium (1000 years).
10 YEARS
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