Pisces, a constellation and the 12th sign of the zodiac. The name means The Fishes. Pisces contains no bright stars. It is bounded by Andromeda on the north, Pegasus on the north and west, Aquarius on the west and south, Cetus on the south and east, and Aries and Triangulum on the east. The vernal equinox, the point where the sun crosses the celestial equator at the beginning of spring, is in Pisces.