|agnəˈskastəs noun
( plural agnus castuses )
Etymology: Middle English, from Latin, by folk etymology (influence of Latin agnus lamb & castus chaste) from Greek agnos (confused with hagnos chaste, holy), perhaps of Semitic origin; akin to Hebrew 'āghan to remain closed in or hidden — more at caste
: an ornamental shrub ( Vitex agnus-castus ) having blue or white flowers and fruit that has been used as a stimulant and carminative — called also chaste tree