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.-the musk shrew.-the desman.