[al-kuh-lahyn-urth, -lin-] 
| any of the group of bivalent metals including barium, radium, strontium, calcium, and, usually, magnesium, the hydroxides of which are alkalis but less soluble than those of the alkali metals. |
| al·ka·line-earth metal (āl'kə-lĭn-ûrth', -līn'-) n. Any of a group of metallic elements, especially calcium, strontium, magnesium, and barium, but generally including beryllium and radium. Also called alkaline earth. |
alkaline-earth metal n.
Any of a group of metallic elements including calcium, strontium, magnesium, barium, beryllium, and radium.