Source : Webster's Revised Unabridged Dictionary (1913)

Miniver \Min"i*ver\, n. [See {Meniver}.]
   A fur esteemed in the Middle Ages as a part of costume. It is
   uncertain whether it was the fur of one animal only or of
   different animals.

Source : WordNet®

miniver
     n : trimming on ceremonial robes consisting of white or light
         gray fur