Pronunciation: mith'ri-da'tizm, mith-rid'a-tizm
Immunity against the action of a poison produced by small and gradually increasing doses of the same.
[Mithridates, King of Pontus (132–63 BCE), supposedly an unsuccessful suicide (by poison) because of repeated small doses taken to become invulnerable to assassination by poison]
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Examples: glitazone, GI cocktail, etc.