longitude
The distance of any point east or west of the Greenwich line, measured in degrees.
The longitude of any point represents its exact location east or west of the Greenwich Line in degrees, expressed in decimals. From the Greenwich Line to its opposite arc 180 degrees away, the longitude is expressed as a positive number to the east and a negative number to the west.
Longitude is one of two geocoordinates used to identify each point on the earth's surface; along with latitude and altitude it can single out any point on earth in three dimensions with respect to the equator, the Greenwich Line, and sea level.
Longitude is an angular position rather than a distance measured in meters. Its east-west coordinate is distinct from latitude, which measures north-south position relative to the equator.