river horse (plural river horses)

1. (poetic) hippopotamus
   • 1851 November 13, Herman Melville, chapter 1, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, OCLC 57395299 ↗:

     It is out of the idolatrous dotings of the old Egyptians upon broiled ibis and roasted river horse, that you see the mummies of those creatures in their huge bake-houses the pyramids.

   • 1849, Charlotte Brontë, Shirley

     Liverpool started and snorted like a river-horse roused among his reeds by thunder.

• hippopotamus