Emily Dickinson Lexicon

AG'NUS-CAS'TUS, n. [AG'NUS CAS'TUS.]

A species of Vitex, so called from the Gr. αγνος, chaste, from its imagined virtue of preserving chastity. The Athenian ladies reposed on the leaves of this plant at the feast of Ceres. The Latin castus, chaste, now added to the name, forms a duplication of the sense. – Encyc.