One of the lanthanides

• Occurs in apatite and monazite and xenotime and ytterbite
• Used in lasers
• Element No. 65
• A metallic element of the rare earth group

WordNet Word definitions in WordNet
n. a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite [syn: Tb , atomic number 65 ]

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1843, from Latinized form of Ytterby , Swedish town near the place where mineral containing the element was found (see Ytterbium ) + -ium .\n

Wiktionary Word definitions in Wiktionary
n. a metallic chemical element (''symbol'' Tb) with an atomic number of 65

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Terbium \Ter"bi*um\, n. [NL., fr. Ytterby, in Sweden. See Erbium .] (Chem.) A rare metallic element, found in certain minerals, as gadolinite and samarskite, with other rare earths such as ytterbium. Symbol Tb. Atomic number 65. Atomic weight 158.925.

Wikipedia Word definitions in Wikipedia
Terbium is a chemical element with symbol Tb and atomic number 65. It is a silvery-white rare earth metal that is malleable , ductile and soft enough to be cut with a knife. Terbium is never found in nature as a free element, but it is contained in many ...