1. (Science: zoology) A North American aquatic fur-bearing rodent (fibre zibethicus). It resembles a rat in colour 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 odour of musk. Called also musquash, musk beaver, and ondatra.
3. (Science: zoology) The desman.