Beryllium (noun)

1. A chemical element with the atomic number 4 and the symbol Be, it is a light, strong, and brittle metal.
2. A beryllium compound or alloy, used in various applications such as aerospace, nuclear, and electronics industries.

Origin:

Beryllium is named after the mineral beryl, which contains beryllium.

Examples:

1. Beryllium is a rare element that is used in making high-strength alloys for aircraft and missiles.
2. The high thermal conductivity of beryllium makes it useful for cooling the cores of nuclear reactors.
3. Beryllium is an important component of the radiation shielding in some x-ray and particle accelerator facilities.
4. Beryllium is a toxic element, and exposure to beryllium dust or fumes can cause serious lung problems.
5. The high stiffness and strength-to-weight ratio of beryllium makes it a popular choice for precision instruments and optics.