[1] : The Collaborative International Dictionary of English v.0.48

caste \caste\, n. pg. casta race, lineage, fr. l. castus pure,
   chaste: cf. f. caste, of same origin.
   1. one of the hereditary classes into which the hindu are
      divided according to the laws of brahmanism.
      1913 webster

   note: the members of the same caste are theoretically of
         equal rank, and same profession or occupation, and may
         not eat or intermarry with those not of their own
         caste. the original are four, viz., the brahmans, or
         sacerdotal order; the kshatriyas, or soldiers and
         rulers; the vaisyas, or husbandmen and merchants; and
         the sudras, or laborers and mechanics. men of no caste
         are pariahs, outcasts. numerous mixed classes, or
         castes, have sprung up in the progress of time.
         1913 webster

   2. a separate and fixed order or class of persons in society
      who chiefly hold intercourse among themselves.
      1913 webster

            the tinkers then formed an hereditary caste.
                                                  --macaulay.
      1913 webster

   to lose caste, to be degraded from the caste to which one
      has belonged; to lose social position or consideration.
      1913 webster
see also:
to lose caste 

[2] : WordNet (r) 2.0

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

[3] : Moby Thesaurus II by Grady Ward, 1.0

68 moby thesaurus words for "caste":
   ashram, blood, body, bracket, branch, category, clan, class,
   colony, commonwealth, commune, community, condition, division,
   echelon, economic class, endogamous group, estate, extended family,
   family, footing, gens, grade, group, grouping, head, heading,
   hierarchy, kin, kinship group, label, level, moiety,
   nuclear family, order, phratria, phratry, phyle, pigeonhole, place,
   position, power structure, precedence, predicament, race, rank,
   rate, rating, rubric, section, sept, set, settlement, social class,
   society, sphere, stage, standing, station, status, strain, stratum,
   subcaste, subdivision, subgroup, suborder, title, totem

Caste >> C Words
Caste, definition of term: Caste
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Caste System >> C Words
Caste System, definition of term: Caste System
caste+system_pag1.html