Source : Webster's Revised Unabridged Dictionary (1913)

Tarpum \Tar"pum\, n. (Zo["o]l.)
   A very large marine fish ({Megapolis Atlanticus}) of the
   Southern United States and the West Indies. It often becomes
   six or more feet in length, and has large silvery scales. The
   scales are a staple article of trade, and are used in
   fancywork. Called also {tarpon}, {sabalo}, {savanilla},
   {silverfish}, and {jewfish}.