From Longman Dictionary of Contemporary Englishwater voleˈwater vole noun [countable] British English HBAan animal like a big mouse that can swim and lives near water SYN water rat
Examples from the Corpus
water vole• A water vole swam vigorously across from a little island, its round face and bright eyes showing above the water.• The muskrat is a swamp-dwelling rodent something like a large water vole.• Rob Strachan stresses that the water vole survey is the first of its kind.• Meanwhile, Strachan views the water vole as an indicator of wetland habitat quality, and he looks forward with little optimism. 