adj. 1 abstaining from extramarital, or from all, sexual intercourse. 2 (of behaviour, speech, etc.) pure, virtuous, decent. 3 (of artistic etc. style) simple, unadorned. chaste-tree an ornamental shrub, Vitex agnus-castus, with blue or white flowers. chastely adv. chasteness n.
[ ME f. OF f. L castus ]