Polar circles Meaning, Definition & Usage

  1. noun a line of latitude at the north or south poles
    polar circle.

WordNet


Definitions
  1. (Astron. & Geog.), two circles, each at a distance from a pole of the earth equal to the obliquity of the ecliptic, or about 23° 28', the northern called the arctic circle, and the southern the antarctic circle.

Webster 1913