Source : Webster's Revised Unabridged Dictionary (1913)

Silverfish \Sil"ver*fish`\, n. (Zo["o]l.)
   (a) The tarpum.
   (b) A white variety of the goldfish.

Source : WordNet®

silverfish
     n 1: silver-gray wingless insect found in houses feeding on book
          bindings and starched clothing [syn: {Lepisma saccharina}]
     2: a silvery variety of Carassius auratus
     [also: {silverfishes} (pl)]