ˈba(a)rēəm, ˈber-, ˈbār- noun
( -s )
Etymology: New Latin, from bar- + -ium
: a silver-white malleable toxic bivalent metallic element of the alkaline-earth group that tarnishes rapidly in air, that occurs only in combination especially as barite and witherite, that is made by reduction of barium oxide or by electrolysis of a fused salt (as barium chloride), and that is used in the form of alloys chiefly as a getter in electron tubes — symbol Ba ; see element table