(feminine) a caste, hereditary Indian socio-religious class (except the 'unclean' lowest) (depreciated in specialist usage)
(feminine) a similarly closed social class, especially if rather impenetrable -notably (de facto) hereditary-, as in Ancient Egypt or various tribal and feudal societies
(feminine) any closed, social and/or hierarchic group, such as a priesthood or a military corps
(feminine, obsolete) national/ethnic group or character
From Portuguese casta (“lineage, race”), from the feminine of casto (“pure, chaste”), from Latin castus (“pure, clean”). Cognate with Danish, Norwegian (see below), German Kaste, English caste, French caste etc.