sea-cow

/S IY1 K AW1/
noun
  1. 1

    Any of several marine mammals of the order Sirenia, including the manatee and dugong.

Synonyms

noun
  1. 1

    Hippopotamus.

Source: https://en.wiktionary.org/wiki/sea%20cow, https://en.wiktionary.org/wiki/sea-cow