[dis-proh-see-uhm, -shee-]
noun Chemistry.
a rare-earth metallic element, highly reactive and paramagnetic, found in small amounts in various rare-earth minerals, as euxenite and monazite: used to absorb neutrons in nuclear reactors. Symbol: Dy; atomic weight: 162.50; atomic number: 66.

1885–90; < Neo-Latin < Greek dysprós(itos) hard to get at (dys- dys- + pros- to + itós, past participle of iénai to go) + -ium

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To dysprosium
World English Dictionary
dysprosium (dɪsˈprəʊsɪəm)
a soft silvery-white metallic element of the lanthanide series: used in laser materials and as a neutron absorber in nuclear control rods. Symbol: Dy; atomic no: 66; atomic wt: 162.50; valency: 3; relative density: 8.551; melting pt: 1412°C; boiling pt: 2567°C
[C20: New Latin, from Greek dusprositos difficult to get near + -ium]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
American Heritage
Medical Dictionary

dysprosium dys·pro·si·um (dĭs-prō'zē-əm, -zhē-əm)
Symbol Dy
A soft, silvery rare-earth element used in nuclear research. Atomic number 66; atomic weight 162.50; melting point 1,411°C; boiling point 2,600°C; specific gravity 8.551; valence 3.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
dysprosium   (dĭs-prō'zē-əm)  Pronunciation Key 
Symbol Dy
A soft, silvery metallic element of the lanthanide series. Because it has a high melting point and absorbs neutrons well, dysprosium is used to help control nuclear reactions. Atomic number 66; atomic weight 162.50; melting point 1,407°C; boiling point 2,600°C; specific gravity 8.536; valence 3. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Encyclopedia Britannica


(Dy), chemical element, rare-earth metal of the lanthanoid series of the periodic table. A relatively hard and very reactive metal, it is oxidized by air and by water. Its high melting point and ability to absorb neutrons make it useful in control rods for nuclear reactors. Its compounds have been used for making laser materials, as components in some electronic equipment, and as phosphor activators

Learn more about dysprosium with a free trial on Britannica.com.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source
Example sentences
Small doses of dysprosium or terbium, for instance, make batteries operate better at high temperatures-a must for electric cars.
Temperature and magnetic field-dependent x-ray powder diffraction study of dysprosium.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature