terbium

American  

[tur-bee-uhm] / ˈtɜr bi əm /

noun

Chemistry.

1. a rare-earth, metallic element present in certain minerals and yielding colorless salts. Tb; 65; 158.924; 8.25.

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terbium British  

/ ˈtɜːbɪəm /

noun

1. a soft malleable silvery-grey element of the lanthanide series of metals, occurring in gadolinite and monazite and used in lasers and for doping solid-state devices. Symbol: Tb; atomic no: 65; atomic wt: 158.92534; valency: 3 or 4; relative density: 8.230; melting pt: 1356°C; boiling pt: 3230°C

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terbium Scientific  

/ tûr′bē-əm /

1. A soft, silvery-gray metallic element of the lanthanide series. It is used in color television tubes, x-ray machines, and lasers. Atomic number 65; atomic weight 158.925; melting point 1,356°C; boiling point 3,123°C; specific gravity 8.229; valence 3, 4.

2. See Periodic Table

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Other Word Forms

• terbic
  adjective

Etymology

Origin of terbium

1835–45; (Yt)terb(y) , name of Swedish town where found + -ium. See ytterbium

Example Sentences

See Examples For:

terbium

Geological Survey geologists first identified rare earth mineralization in the Music Valley area in 1954, with sampling reporting enrichment in dysprosium, terbium, yttrium and ytterbium, Dateline Resources said in a press release.

From Los Angeles Times ● Mar. 30, 2026

The rugged hills surrounding Ganzhou are home to the world's largest mining and processing operations of the strategic "heavy" elements, including dysprosium, yttrium and terbium.

From Barron's ● Dec. 21, 2025

Certain powerful types of rare-earth magnets—often used for car engines, robotics and industrial machinery—typically use small quantities of dysprosium and terbium, two “heavy” rare-earth elements, to allow magnets to function at high temperatures.

From The Wall Street Journal ● Dec. 2, 2025

Rare earths, like samarium and terbium, are critical to the production of technologies set to shape the world in the coming decades – including electric vehicles and highly advanced weapons systems.

From BBC ● Apr. 25, 2025

Who, then, will be the first to discover a use for indium, germanium, terbium, thulium, lanthanum, neodymium, scandium, samarium and others as unknown to us as tungsten was to our fathers?

From Creative Chemistry Descriptive of Recent Achievements in the Chemical Industries by Slosson, Edwin E.