yttrium

noun

yt·​tri·​um ˈi-trē-əm 

: a metallic element with atomic number 39 usually included in the rare-earth group that occurs usually with other rare earth elements in minerals and is used especially in phosphors, YAG lasers, alloys, and treatments for certain cancers see Chemical Elements Table

Examples of yttrium in a Sentence

Recent Examples on the Web

Those rare earths included samarium, gadolinium, terbium, dysprosium, lutetium, scandium, and yttrium. —Steve Banker, Forbes.com, 12 May 2025

China placed new restrictions on seven heavy rare earth minerals on April 4, including scandium and yttrium, in retaliation against U.S. tariffs. —Alain Sherter, CBS News, 2 May 2025

Around 93% of US imports of yttrium compounds came from China in the four years through 2023, according to the US Geological Survey. —Bloomberg, Mercury News, 17 Apr. 2025

The new restrictions — which encompass the medium and heavy rare earth elements samarium, gadolinium, terbium, dysprosium, lutetium, scandium and yttrium — will require Chinese companies to secure special licenses to export the resources. —Dylan Butts, CNBC, 15 Apr. 2025

Word History

Etymology

New Latin, from yttria yttrium oxide (Y₂O₃), irregular from Ytterby, town in southern Sweden

First Known Use

1814, in the meaning defined above

Kids Definition

yttrium

noun

yt·​tri·​um ˈi-trē-əm 

: a metallic element that occurs in minerals along with other similar uncommon elements see element

Medical Definition

yttrium

noun

yt·​tri·​um ˈi-trē-əm 

: a trivalent metallic element usually included among the rare earth elements which it resembles chemically and with which it occurs in minerals

—symbol Y see Chemical Elements Table