1. (Science: zoology) a shark of the genus Sphyrna or Zygaena, having the eyes set on projections from the sides of the head, which gives it a hammer shape. The Sphyrna zygaena is found in the North atlantic. Called also hammer fish, and balance fish.
2. (Science: zoology) a fresh water fish; the stone-roller.
3. (Science: zoology) An african fruit bat (Hypsignathus monstrosus); so called from its large blunt nozzle.