Definitions for water rat
Random House Webster's College Dictionary
any of various aquatic rodents, as the muskrat.
Slang. a vagrant or thief who frequents a waterfront.
Origin of water rat:
water dog, water rat(noun)
a person who enjoys being in or on the water
water vole, water rat, Arvicola amphibius(noun)
common large Eurasian vole
any of various amphibious rats
any of various rodents from Florida and southern Georgia, especially Neofiber alleni; the muskrat
the Eurasian water vole
a petty thief or waterfront ruffian
a person fond of water sports
A member of the water police.
the water vole. See under Vole
the beaver rat. See under Beaver
a thief on the water; a pirate