Gad`o*lin"i*a\, n. [NL. See Gadolinite.] (Chem.) A rare earth, regarded by some as an oxide of the supposed element gadolinium, by others as only a mixture of the oxides of yttrium, erbium, ytterbium, etc.
Gad`o*lin"i*a\, n. [NL. See Gadolinite.] A rare earth associated with yttria and regarded as the oxide (Gd2O3) of a metallic element,