a common, omnivorous large rat (Rattus norvegicus) that swims and dives well, usually lives in underground burrows, and spreads various diseases: the mutant form, a white rat, is used for medical experiments
The common domestic rat (Rattus norvegicus), which is found worldwide and is a destructive pest of crops and stored food and a carrier of disease. Also called Norway rat.
(plural brown rats)
- A species of rat, Rattus norvegicus, common worldwide.