noun

meridian

meridian, line of longitude

The prime meridian passes through Greenwich.

The prime meridian passes through Greenwich.

The sun reaches its meridian at noon.

The sun reaches its meridian at noon.

((a/the/prime)) meridian an imaginary line on the earth's surface The prime meridian is an imaginary line.

Synonyms: line of longitude, great circle

From Latin `meridies` (midday), from `medius` (middle) + `dies` (day).

Think of 'meri-' like 'middle' and '-dian' like 'day' (from Latin `dies`). It's the line where it's the 'middle of the day' (noon) at the same time.

This page is designed for learning support. Please use it as a learning reference, not as a formal reference.