Source : Webster's Revised Unabridged Dictionary (1913)

Indium \In"di*um\, n. [NL. See {Indigo}.] (Chem.)
   A rare metallic element, discovered in certain ores of zinc,
   by means of its characteristic spectrum of two indigo blue
   lines; hence, its name. In appearance it resembles zinc,
   being white or lead gray, soft, malleable and easily fusible,
   but in its chemical relation it resembles aluminium or
   gallium. Symbol In. Atomic weight, 113.4.

Source : WordNet®

indium
     n : a rare soft silvery metallic element; occurs in small
         quantities in sphalerite [syn: {In}, {atomic number 49}]