The New Dictionary of Cultural Literacy, Third Edition. 2002.
caste
(KAST) One of the four hereditary social divisions in Hinduism. Members of any one caste are restricted in their choice of occupation and may have only limited association with members of other castes.
Caste has come to mean a group of persons set apart by economic, social, religious, legal, or political criteria, such as occupation, status, religious denomination, legal privilege, skin color, or some other physical characteristic. Members of a caste tend to associate among themselves and rarely marry outside the caste. Castes are more socially separate from each other than are social classes.