Source : Webster's Revised Unabridged Dictionary (1913)

Muskrat \Musk"rat`\, n.
   1. (Zo["o]l.) A North American aquatic fur-bearing rodent
      ({Fiber zibethicus}). It resembles a rat in color and
      having a long scaly tail, but the tail is compressed, the
      bind 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}, and {ondatra}.

Source : WordNet®

Ondatra
     n : muskrats [syn: {genus Ondatra}]