ondatra zibethica

from WordNet (r) 3.0 (2006)

Ondatra zibethica
    n 1: beaver-like aquatic rodent of North America with dark
         glossy brown fur [syn: {muskrat}, {musquash}, {Ondatra
         zibethica}]

from The Collaborative International Dictionary of English v.0.48

Ondatra \Ondatra\ prop. n.
   A genus of rodents including the muskrat ({Ondatra
   zibethica}).

   Syn: genus {Ondatra}.
        [WordNet 1.5]

from The Collaborative International Dictionary of English v.0.48

Muskrat \Musk"rat`\, n.
   1. (Zool.) A North American aquatic fur-bearing rodent
      ({Ondatra zibethica} formerly {Fiber zibethicus}). It
      resembles a rat in color and having a long scaly tail, but
      the tail is compressed, the hind feet are webbed, and the
      ears are concealed in the fur. It has scent glands which
      secrete a substance having a strong odor of musk. Called
      also {musquash}, {musk beaver}, {ondatra}, and sometimes
      {water rat}.
      [1913 Webster +PJC]

   2. (Zool.) The musk shrew.
      [1913 Webster]

   3. (Zool.) The desman.
      [1913 Webster]