DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   caste
       n 1: social status or position conferred by a system based on
            class; "lose caste by doing work beneath one's station"
       2: (Hinduism) a hereditary social class among Hindus; stratified
          according to ritual purity
       3: a social class separated from others by distinctions of
          hereditary rank or profession or wealth
       4: in some social insects (such as ants) a physically distinct
          individual or group of individuals specialized to perform
          certain functions in the colony