Palladium (noun)

1. A chemical element with the atomic number 46 and symbol Pd. It is a white, precious metal that is similar in appearance to platinum, and is used in jewelry, dentistry, and the aerospace industry.
2. A thing, person, or organization that provides protection or security.

Origin:

From latin palladium, from greek palladion, the name of the statue of pallas athena that was said to have been brought to troy by aeneas and to have protected the city.

Examples:

1. The palladium in the catalytic converter reduces harmful emissions from car exhausts.
2. The ring was made of palladium and had a beautiful white luster.
3. The palladium coin was highly valued and sought after by collectors.
4. The palladium alloy was used to make the dental bridge.
5. The city was considered a palladium of democracy in the region.