a vigorous thrust of cold, polar air across temperate regions.
plural noun 1. the regions within the Arctic and Antarctic circles.
- Polar sequence
noun 1. (astronomy) a series of stars in the vicinity of the N celestial pole whose accurately determined magnitudes serve as the standard for visual and photographic magnitudes of stars
- Polar star
polar star n. See daughter star.
- Polar wander
noun 1. (geology) the movement of the earth’s magnetic poles with respect to the geographic poles