noun Chemistry.
- any of the oxides of barium, radium, strontium, calcium, and, sometimes, magnesium.
noun
- Also called: alkaline earth metal, alkaline earth element any of the divalent electropositive metals beryllium, magnesium, calcium, strontium, barium, and radium, belonging to group 2A of the periodic table
- an oxide of one of the alkaline earth metals
n.
- The oxides of calcium, strontium, radium, and barium, and sometimes magnesium.