DCHP-1 Online
water-rat 
n. an aquatic rodent, Ondatra zibethica, common to many parts of North America and widely trapped for its valuable fur.
See also: muskrat (def. 1)
- 1912 (c1902) The water-rat has tried to hide in the under-tangle; and the ermine has not only dived in pursuit but headed the water-rat back from the safe retreat of his house.
- 1944 "Mr. Weasel is a good swimmer! He can catch a water-rat, out-divin' an' out-swimmin' him with ease . . . ."
- 1912 (c1902) The water-rat has tried to hide in the under-tangle; and the ermine has not only dived in pursuit but headed the water-rat back from the safe retreat of his house.