toxicologyPronunciation: /ˌtɒksɪˈkɒlədʒi/Translate toxicology | into Italian Definition of toxicology noun [mass noun] the branch of science concerned with the nature, effects, and detection of poisons. Derivatives toxicologicalPronunciation: /-kəˈlɒdʒɪk(ə)l/ adjective toxicologically adverb toxicologist noun toxicology in other Oxford dictionaries Definition of toxicology in the US English dictionary