Barium n. : One of the elements, belonging to the alkaline earth group; a metal having a silver-white color, and melting at a very high temperature. It is difficult to obtain the pure metal, from the facility with which it becomes oxidized in the air. Atomic weight, 137. Symbol, Ba. Its oxide called baryta.

Example:
How does Barium sulfate taste compared to the halflytley stuff they give you for a colonoscopy?

Taxonomy
barium, Ba, barium compounds, metal, minerals, Barium sulfate, 06-06, BaSO4, Isotopes, mineral barite, kJ, free encyclopedia, BaCl2, BaO, GPa, Barium carbonate, doses, stable isotopes.

Defination from the web:
Hyperlinked overview of the element featuring notable characteristics, applications, history, occurrence, compounds, isotopes, and precautions.