Line_of_longitudeWordNet Explorer

an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator

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

a meridian that passes through the observer's zenith

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

an imaginary line passing through both magnetic poles of the Earth