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}.