meridian

Everyday

1. A meridian is an imaginary line on the globe or a map that runs from the North Pole to the South Pole; lines of longitude are meridians. tree →
2. The Prime Meridian is the meridian at 0° longitude that passes through Greenwich in London, from which other places are measured east or west. tree →
3. (old, poetic) The meridian is the highest point of the sun at midday, or the peak of something. tree →
4. In Chinese medicine, meridians are believed paths of energy in the body (a belief, not proved by science). tree →

In the lessons

In geography and maths lessons, pupils use meridians (longitude) and parallels (latitude) as a grid to find places; time zones are based on meridians. At Greenwich, visitors stand with one foot each side of the Prime Meridian. Phrases: «the Prime Meridian», «Greenwich Meridian», «lines of longitude».

Examples

• The Prime Meridian passes through Greenwich. tree →
• Meridians run from pole to pole. tree →
• London is on the 0° meridian. tree →
• I stood with one foot in each hemisphere on the meridian line. tree →
• Lines of longitude are also called meridians. tree →
• Places east of the Prime Meridian are ahead in time. tree →

Note

Countable. Meridians (longitude) run north–south; parallels (latitude) run east–west. In maths and time problems: the Earth turns 360° in 24 hours, so every 15° of longitude is about one hour of time difference.