from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Any of various oxides of the rare-earth elements.
  • noun A rare-earth element.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun chemistry naturally occurring oxides of the lanthanide metals; they are widely distributed in relatively small concentrations and are used in glassmaking, ceramic glazes etc

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun any element of the lanthanide series (atomic numbers 57 through 71)


from The American Heritage® Dictionary of the English Language, 4th Edition

[rare (because the minerals from which the rare-earth elements were first isolated are uncommon) + earth, metallic oxide.]


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  • "The Prius hybrid automobile is popular for its fuel efficiency, but its electric motor and battery guzzle rare earth metals, a little-known class of elements found in a wide range of gadgets and consumer goods."


    August 31, 2009

  • common ground - rarely refound

    an exercise of hum(us)ilty

    September 29, 2011