(literally) A rat that lives on or along a river. / (chiefly derogatory) A lower-class person living on or along a river.

(informal) A soldier trained to enter enclosed enemy spaces like tunnel systems to search them and eliminate and/or capture any occupants.

A gerbil (subfamily Gerbillinae) of the deserts of Africa and Asia / A kangaroo rat (genus Dipodomys) from North America / A Natal multimammate mouse (Mastomys natalensis) from Africa

(slang) person who lives and exhibits attitudes of inner city life. usually a negative connotation that implies poor upbringing, bad manners, little to no education and low class behavior

(idiomatic) A small, usually minor road used by a significant amount of traffic as a short cut or to avoid congestion on more major routes.

(idiomatic) To drive through residential streets to avoid congestion on the main roads.

plural of river rat

plural of tunnel rat

The brown rat.

A species of rat, Rattus norvegicus, common worldwide.