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1. A meridian used as a reference line from which longitude east and west is measured.
2. Prime Meridian The meridian passing through Greenwich, England, designated as the zero meridian (0°) by an international conference in 1884.
(Physical Geography) the 0° meridian from which the other meridians or lines of longitude are calculated, usually taken to pass through Greenwich
the meridian running through Greenwich, England, from which longitude east and west is reckoned.
The meridian with a longitude of 0°, used as a reference line from which longitude east and west is measured. It passes through Greenwich, England.
An imaginary north-south line of longitude that passes through Greenwich, England, and is used as the basis for longitudinal measurements on the globe.
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|Noun||1.||prime meridian - meridian at zero degree longitude from which east and west are reckoned (usually the Greenwich longitude in England)|