beryllium

n. (Be) lightweight metallic chemical element commonly used in alloys

Beryllium (IPA: ) is the chemical element that has the symbol Be and atomic number 4. A  bivalent element, elemental beryllium is a steel grey, strong, light-weight yet brittle, alkaline earth metal. It is primarily used as a hardening agent in alloys (most notably beryllium copper).
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Noun
1. a light strong brittle gray toxic bivalent metallic element
(synonym) Be, glucinium, atomic number 4
(hypernym) metallic element, metal
(substance-holonym) beryl

n. beryllium, lightweight metallic chemical element commonly used in alloys

n. beryllium