antimeridian (noun)
1
(geography) The reference line at 180° longitude, on the opposite side of earth to the prime meridian.
2
(geography) A meridian of longitude opposite to any given meridian used as a point of reference.
(geography) The reference line at 180° longitude, on the opposite side of earth to the prime meridian.
(geography) A meridian of longitude opposite to any given meridian used as a point of reference.