Dictionary.net

A genus of the order Sirenia characterized by a notched tail, the presence of nasal bones and a long nasal cavity, and large columnar teeth lacking enamel. Dugongs inhabit the coastal waters of the Indian Ocean, Red Sea, and the Malay Archipelago. (From Scott, Concise Encyclopedia Biology, 1996)

n. [Malayan] A swimming mammal of the East Indian seas having the aquatic habits of the whales, but herbivorous, and referred to a separate group.