line of longitude

Synonyms:

meridian

Examples:

International Date Line

an imaginary line on the surface of the earth following (approximately) the 180th meridian

Greenwich Meridian

the meridian passing through Greenwich; was internationally adopted as the earth's zero of longitude in 1884

Types:

observer's meridian

a meridian that passes through the observer's zenith

prime meridian

meridian at zero degree longitude from which east and west are reckoned (usually the Greenwich longitude in England)

magnetic meridian

an imaginary line passing through both magnetic poles of the Earth

Type of:

great circle

a circular line on the surface of a sphere formed by intersecting it with a plane passing through the center