1540s, "stone used as an antidote against poison," via Medieval Latin, from Arabic bazahr, from Persian pad-zahr "counter-poison," from pad "protecting, guardian, master" (from Iranian *patar-, source also of Avestan patar-, from PIE *pa-tor-, from root *pa- "to feed, protect") + zahr "poison" (from Old Iranian *jathra, from PIE *gwhn-tro-, from root *gwhen- "to strike, kill;" see bane). Later in reference to a concoction from solid matter found in the stomachs and intestines of ruminants, which was held to have antidotal qualities (1570s). Related: Bezoardic.