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thallium

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noun thal·li·um \ˈtha-lē-əm\

Definition of thallium

  1. :  a soft poisonous metallic element that resembles lead in physical properties, occurs sparsely in a number of common ores, and is used chiefly in the form of compounds especially in photosensitive devices and formerly as a pesticide — see element table



Origin of thallium

New Latin, from Greek thallos green shoot; from the bright green line in its spectrum


First Known Use: 1861

Rhymes with thallium


Medical Dictionary

thallium

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noun thal·li·um \ˈthal-ē-əm\

Medical Definition of thallium

  1. :  a sparsely but widely distributed poisonous metallic element that resembles lead in physical properties and is used chiefly in the form of compounds in photoelectric cells or as a pesticide—symbol Tl; see element table




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