NOUN (2)

1. (Roman mythology) goddess of agriculture; counterpart of Greek Demeter;

2. the largest asteroid and the first discovered;

The Collaborative International Dictionary of English v.0.48:

Ceres \Ce"res\, n. [L., Ceres, also corn, grain, akin to E.
   create.]
   1. (Class. Myth.) The daughter of Saturn and Ops or Rhea, the
      goddess of corn and tillage.
      [1913 Webster]

   2. (Actron.) The first discovered asteroid.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Ceres
    n 1: (Roman mythology) goddess of agriculture; counterpart of
         Greek Demeter
    2: the largest asteroid and the first discovered