Real Dictionary

beryllium in American English
a hard, silver-white, metallic chemical element, one of the alkaline-earth metals, found only in combination with others: it forms strong, hard, lightweight alloys with several metals: symbol, Be; at. no., 4
noun: a steel-gray, bivalent, hard, light, metallic element, the salts of which are sweet: used chiefly in copper alloys for better fatigue endurance, in springs, and in electrical contacts; at. wt.: 9.0122; at. no.: 4; sp. gr.: 1.8 at 20° C

beryllium in British English
noun: a corrosion-resistant toxic silvery-white metallic element that occurs chiefly in beryl and is used mainly in X-ray windows and in the manufacture of alloys. Symbol: Be; atomic no: 4; atomic wt: 9.012; valency: 2; relative density: 1.848; melting pt: 1289