Definition of prime meridian in US English:

prime meridian

noun

  • 1A planet's meridian adopted as the zero of longitude.

    • ‘The prime meridian is the line that separates geographic east from west on the globe.’
    • ‘On the earliest charts displaying a longitude scale, the prime meridian passed through the Canaries.’
    • ‘Zero degrees longitude, the prime meridian could be anywhere - and has been, from the designated home ports of Rome to Paris to Jerusalem to Philadelphia to St. Petersburg.’
    • ‘That's the instant the sun is aligned with the degree line of longitude, or the prime meridian - also called the Greenwich Meridian.’
    • ‘In this sense London marked the prime meridian in a cultural cartography too - a global chronocultural geography.’
    • ‘Only on the fine line of the prime meridian, on that ‘great Greenwich hill and tower’ of the celestial seat, will chronometrical time be the ‘right time.’
    • ‘But the creation of the prime meridian helped set international standards for how time is measured, for when a day begins and ends - even for how long an hour is.’
    • ‘In a strong sense, then, a fiddler crab's frame of reference - the equator and prime meridian of its entire world - is centered on its burrow.’
    • ‘Because of Britain's sustained support for achievements in astronomical and navigational measurement, the Royal Observatory Greenwich landed the prime meridian.’
    • ‘This forthcoming transit is centered on about 08: 20, Universal Time (UT: the standard time for the prime meridian passing through the Greenwich Observatory in London, England).’
    • ‘Seventeenth century navigators could tell local time from the position of the Sun, but to determine their longitude, they needed also to know the time at a fixed reference point, i.e. Greenwich, the location of the prime meridian.’
    • ‘The prime meridian is the line which runs through Greenwich Observatory and is used globally as a standard ‘zero’ point.’
    • ‘The first prime meridian was established by Hipparchus of Rhodes in the 2nd century BC.’
    • ‘Fourthly, lights out in this wing is extended from the ten thirty curfew that was given to you before your acceptance into this team, to eleven o'clock prime meridian.’
    • ‘And it's where time itself starts, being the site of the prime meridian, Greenwich Mean Time or degrees longitude, depending on what you prefer.’
    • ‘Key amongst the equipment here was the transit telescope, angled to move only up and down, and from 1750 it was this telescope that defined Britain's prime meridian.’
    1. 1.1usually the prime meridian The earth's zero of longitude, which by convention passes through Greenwich, England.
      • ‘The prime meridian is the line that separates geographic east from west on the globe.’
      • ‘On the earliest charts displaying a longitude scale, the prime meridian passed through the Canaries.’
      • ‘A further difficulty was the question of the position of the prime meridian.’
      • ‘The prime meridian is the line which runs through Greenwich Observatory and is used globally as a standard ' zero ' point.’
      • ‘In case you didn't know, this city is famous for being the home of the prime meridian, hence Greenwich Mean Time.’

Pronunciation

prime meridian

/prīm məˈridēən/