Definition of "hippo"

There was an old hippo that had the bad habit of getting out on the bank and roaming at night over the station grounds.

1899 February, Joseph Conrad, “The Heart of Darkness”, in Blackwood’s Edinburgh Magazine, volume CLXV, number M, New York, N.Y.: The Leonard Scott Publishing Company, […], part I, page 218

"I've seen them buryin' a chief up the Aruwimi River, and they ate a hippo that must have weighed as much as a tribe."

1913, Arthur Conan Doyle, “(please specify the page)”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton

The Eastern Cape village whose dam has been taken over by a hippo will decide next week what happens to the animal.

2006 June 24, The Weekend Argus