chaste (adj.)

1610s, "one of the hereditary social groups of India," from Portuguese casta "breed, race, caste," earlier casta raça, "unmixed race," from Latin castus "cut off, separated" (also "pure," via notion of "cut off" from faults), past participle of carere "to be cut off from," from PIE *kas-to-, from root *kes- "to cut." Caste system is recorded from 1840. An earlier, now-obsolete sense of caste in English is "a race of men" (1550s), from Latin castus "chaste."

Of the castes, the first three are the natural and gradually established divisions of the Aryan invaders and conquerors of India; the fourth was made up of the subjugated aborigines. The Sanskrit name for caste is varna, color, the different castes having been at first marked by differences of complexion, according to race, and in some degree according to occupation and consequent exposure. [Century Dictionary, 1895]

c. 1200, chastete, "sexual purity" (as defined by the Church), including but not limited to virginity or celibacy, from Old French chastete "chastity, purity" (12c., Modern French chasteté), from Latin castitatem (nominative castitas) "purity, chastity" from castus "cut off, separated; pure" (see caste). Chastity-belt is from 1894 (belt of chastity is from 1878).

Chastity is merely a social law created to encourage the alliances that most promote the permanent welfare of the race, and to maintain woman in a social position which it is thought advisable she should hold. [Saturday Review, Aug. 10, 1867, quoted in Lecky, "History of European Morals," 1869]