Greenwich mean time

noun, often capitalized M&T
Green·​wich mean time | \ ˈgri-nij- How to pronounce Greenwich mean time (audio) , ˈgre-, -nich-\

Definition of Greenwich mean time

: the mean time of the meridian of Greenwich used historically as the prime basis of standard time throughout the world

called also Greenwich time

— compare coordinated universal time

First Known Use of Greenwich mean time

1863, in the meaning defined above

History and Etymology for Greenwich mean time

Greenwich, England

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The first known use of Greenwich mean time was in 1863

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Greenwich mean time


English Language Learners Definition of Greenwich mean time

: the time in Greenwich, England, that is used as the basis of standard time throughout the world

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