1. Any of the hereditary, endogamous social classes or subclasses of traditional Hindu society, stratified according to Hindu ritual purity, especially the Brahmin, Kshatriya, Vaisya, and Sudra castes.
2. A social class separated from others by distinctions of hereditary rank, profession, or wealth.
a. A social system or the principle of grading society based on castes.
b. The social position or status conferred by a system based on castes: lose caste by doing work beneath one's station.
4. A specialized level in a colony of social insects, such as ants, in which the members, such as workers or soldiers, carry out a specific function.
[Spanish casta, race, and Portuguese casta, race, caste, both from feminine of casto, pure, from Latin castus; see kes- in the Appendix of Indo-European roots.]
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