in Astronomy, an epithet given to the north pole, or the pole raised above our horizon. It is called the arctic pole, on occasion of the constellation of the little bear, in Greek called αρκτος; the last star in the tail whereof nearly points out the north pole.

Arctic Circle is a lesser circle of the sphere, parallel to the equator, and 23° 50' distant from the north pole; from whence its name. This, and its opposite, the antarctic, are called the two polar circles; and may be conceived to be described by the motion of the poles of the ecliptic, round the poles of the equator, or of the world.