caste

Etymology

Borrowed from Portuguese or Spanish casta (“lineage, breed, race”), of uncertain origin. The OED derives it from Portuguese casto (“chaste”), from Latin castus. Coromines (1987) argues instead for a hypothetical Gothic form *𐌺𐌰𐍃𐍄𐍃 (*kasts), cognate with English cast, from Proto-Germanic *kastuz, from Proto-Indo-European *h₂ǵ-es-.

noun

1. Any of the hereditary social classes and subclasses of South Asian societies.
   Pakistan is a conservative, religious state. The Edhi Foundation is unusual in its ignoring of caste, creed, religion and sect. This strict stance has led to some criticism from religious groups. April 6, 2017, Samira Shackle, “On the frontline with Karachi’s ambulance drivers”, in the Guardian
2. A separate and fixed order or class of persons in society who chiefly associate with each other.
   'I believe, Messieurs, in loyalty - to one's friends and one's family and one's caste.' 1934, Agatha Christie, chapter 5, in Murder on the Orient Express, London: HarperCollins, published 2017, page 236
3. (zoology) A class of polymorphous eusocial insects of a particular size and function within a colony.
   In beehives, most bees belong to the worker caste.