Noun 1. any of the bivalent metals of group II of the periodic table (calcium or strontium or barium or magnesium or beryllium) (synonym) alkaline-earth metal (hypernym) metallic element, metal
family of group IIA elements, beryllium, Be, magnesium, Mg, calcium, Ca, strontium, Sr, barium, Ba, and radium, Ra. The oxides and hydroxides of these elements are strong bases. See also, alkaline.