rare earth

American  

noun

Chemistry.

1. the oxide of any of the rare-earth elements contained in various minerals.

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rare earth British  

noun

1. any oxide of a lanthanide

2. Also called: rare-earth element.  another name for lanthanide

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Etymology

Origin of rare earth

First recorded in 1875–80

Example Sentences

Last month, Lynas began producing samarium oxide, a difficult-to-source rare earth in high military demand that is used in heat-resistant magnets for jet fighters and missiles.

From The Wall Street Journal • Apr. 26, 2026

“No one had made a separated heavy rare earth outside of China in 20 years,” said Amanda Lacaze, Lynas’s chief executive.

From The Wall Street Journal • Apr. 26, 2026

“The Western rare earth sector stands at a critical inflection point, as governments and strategic industries urgently seek reliable sources of critical rare earths — particularly scarce heavy rare earths.”

From MarketWatch • Apr. 20, 2026

More than a quarter of that tonnage is heavy rare earth oxides, which are used in defense, clean energy, and technology applications.

From Barron's • Apr. 17, 2026

The same rare earth out of which the world famous Etruscan pottery is manufactured in the little village of Etrusca, near Milan, Italy.

From Young Wallingford by Chester, George Randolph