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English definition of “millennium”

millennium

noun [C] uk   /mɪˈlen.i.əm/ (plural millennia or millenniums) us  
C2 a period of 1,000 years, or the time when a period of 1,000 years ends: The corpse had lain preserved in the soil for almost two millennia. How did you celebrate the Millennium?
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Decades, centuries and the millennium
millennial
adjective uk   /-əl/ us  
Decades, centuries and the millennium
(Definition of millennium from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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