sodium
n. uncountablen. a soft, silver-white metal that is very common in nature. You usually find it in salt, and it is an important mineral for your body.
n. a soft, silver-white, highly reactive alkali metal with the atomic number 11. It occurs naturally only in compounds, most notably as a component of common table salt.
The doctor told him to eat less sodium.
Processed foods often contain high levels of sodium to improve their flavor and shelf life.
In its pure elemental form, sodium reacts violently with water to produce hydrogen gas and a strong alkaline solution, making it a staple of chemistry demonstrations.
Coined by British chemist Humphry Davy in 1808, from soda + -ium.
Uncountable when referring to the chemical element or dietary mineral; countable only in technical contexts referring to specific isotopes or chemical states.