Source : Webster's Revised Unabridged Dictionary (1913)

Neodymium \Ne`o*dym"i*um\, n. [NL. Dee {Neo-}, and {Didymium}.]
   (Chem.)
   An elementary substance which forms one of the constituents
   of didymium. Symbol Nd. Atomic weight 140.8.

Neodymium \Ne`o*dym"i*um\, n. [NL. See {Neo-}, {Didymium}.]
   (Chem.)
   A rare metallic element occurring in combination with cerium,
   lanthanum, and other rare metals, and forming
   amethyst-colored salts. It was separated in 1885 by von
   Welsbach from praseodymium, the two having previously been
   regarded as a single element (didymium). It is chiefly
   trivalent. Symbol Nd; at. wt. 144.3.

Source : WordNet®

neodymium
     n : a yellow trivalent metallic element of the rare earth group;
         occurs in monazite and bastnasite in association with
         cerium and lanthanum and praseodymium [syn: {Nd}, {atomic
         number 60}]