Definitions for "Cardinal signs"
Aries, Cancer, Libra, and Capricorn, which fall naturally at the cardinal points in a horoscope; east, north, west, and south, respectively, points indicated by the angles. Cardinal signs are associated naturally with the angular (cardinal) houses; the first, fourth, seventh, and tenth.
these are the signs of Aries, Cancer, Libra, and Capricorn, and are related to the change of the seasons.
see Vital signs