barium
/ˈbeərɪəm/noun
mass noun
1- the chemical element of atomic number 56, a soft white reactive metal of the alkaline earth group. (Symbol: Ba)（化学元素）钡（符号： Ba）。
1.1
- a mixture of barium sulphate and water, opaque to X-rays, which is swallowed to permit radiological examination of the stomach or intestines（作肠胃检查时吞食的）硫酸钡和水的混合物：
as modifier a barium meal.钡餐。
Barium compounds are used in water purification, the glass industry, and pigments, and as an ingredient of signal flares and fireworks, to which they give a bright yellowish-green colour. Barium oxide is a component of high-temperature superconductors.
词源
early 19th cent.: from BARYTA+-IUM.