Lanthanum (noun)

1. A metallic chemical element with the symbol La and atomic number 57.
2. A soft, silvery-white metal used in the production of various alloys, and as a component in batteries and catalysts.

Origin:

Named after the greek word 'lanthanein' meaning 'to lie hidden' because it was difficult to obtain.

Examples:

1. Lanthanum is a rare earth metal that is used in the production of various alloys.
2. The properties of lanthanum make it an important component in batteries and catalysts.
3. Lanthanum has a high melting point and is relatively stable in air.
4. Lanthanum is used in many high-tech applications, such as in the production of cameras and mobile phones.
5. The lanthanum metal is obtained from minerals such as monazite and bastnasite.