longitude science definition

1. A measure of relative position east or west on the Earth's surface, given in degrees from a certain meridian, usually the prime meridian at Greenwich, England, which has a longitude of 0°. The distance of a degree of longitude is about 69 statute miles or 60 nautical miles (111 km) at the equator, decreasing to zero at the poles. Longitude and latitude are the coordinates used to identify any point on the Earth's surface. Compare latitude.
2. Celestial longitude.

longitude