Meridian

Meridian or a meridian line (from Latin meridies via Old French meridiane, meaning “midday”) may refer to

==Science== Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon Central meridian (astronomy) Meridian (geography), a longitude line, i.e. a line of constant longitude, or in other words an imaginary arc on the Earth's surface from the North Pole to the South Pole Meridian arc, the distance between two points with the same longitude Prime meridian, origin of longitudes Principal meridian, arbitrary meridians used as references in land surveying Meridian line, used with a gnomon to measure solar elevation and time of year Autonomous sensory meridian response, a static-like or tingling sensation on the skin Meridian (vision), polar coordinate system for the visual field