|the imaginary circle round the earth, parallel to the equator, at latitude 66° 32′ N; it marks the northernmost point at which the sun appears above the level of the horizon on the winter solstice|
|Arctic Circle (ärk'tĭk) Pronunciation Key
The parallel of latitude approximately 66°33' north. It forms the boundary between the North Temperate and North Frigid zones.
Imaginary circle around the Earth about three-quarters of the way from the equator to the North Pole. North of this line is the “Land of the Midnight Sun,” where the sun never sets on the summer solstice.
Note: The Arctic Circle corresponds to the Antarctic Circle in the Southern Hemisphere.