n. a hallucinogenic agent found in the root of the African forest plant Tabernanthe iboga. It is used mainly by adherents of the Bwiti (or Bouiti) religion in rituals or as a stimulant, although data suggest that ibogaine may have potential clinical use in the treatment of substance dependence and management of withdrawal symptoms it blocks serotonin reuptake and is also an agonist at kappa opioid receptors.