Pisces

n. pl.
  1. (Astron.) The class of Vertebrata that includes the fishes. The principal divisions are Elasmobranchii, Ganoidei, and Teleostei.
    1. The twelfth sign of the zodiac, marked &pisces_; in almanacs.
    2. A zodiacal constellation, including the first point of Aries, which is the vernal equinoctial point; the Fish.