cardinal sign

noun Astrology.
  1. any of the four astrological signs, Aries, Cancer, Libra, or Capricorn, that begin at the equinoxes and solstices, thus marking the beginning of the seasons: characterized by the attribute of strong initiative.
Compare quadruplicity.

Origin of cardinal sign

Middle English word dating back to 1350–1400
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018