noun
barium
BAIR-ee-uhm/ˈberiəm/
A soft, silvery metallic chemical element.
The laboratory stores barium under carefully controlled conditions.
Etymology
The root meaning “heavy” refers to barytes, the mineral in which barium was found, rather than to the metal itself. The ending marks it as a chemical element.
In context
if you put these flatworms in a solution of barium- barium is a non-specific potassium channel blocker; it blocks the ability of these cells to exchange potassium with the outside world