the lines that go up and down, south and north on a map, like the prime meridian.
meridians or lines of longitude
Meridians are lines of longitude that are drawn from the North to South poles.
A common nickname for lines of longitude is "meridians."
Meridians of Longitude All of the other meridians; the lines of longitude.
Meridians are lines of longitude that pass from the North to the South poles.
The meridians meet at the poles, which are the points on Earth's surface where the lines of longitude converge. At the North Pole, all lines of longitude meet, and the same is true for the South Pole.
meridians
lines of longitude
"Lines" of constant longitude are "meridians".
On a Mercator projection, meridians appear as straight, parallel lines running from top to bottom of the map, spaced evenly apart. This is because the Mercator projection is a cylindrical map projection that preserves straight lines of constant bearing, resulting in meridians being stretched vertically towards the poles.
meridians
lines of longitude