rare earth

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

Main Entry: rare earth
Pronunciation: "rer-'&rth
Function: noun
1 : any of a group of similar oxides of metals or a mixture of such oxidesoccurring together in widely distributed but relatively scarce minerals
2 : RARE EARTH ELEMENT

rare earth n.
See lanthanide.