What is "river rat"

n. 1 (context literally English) A rat that lives on or along a river. 2 (context chiefly pejorative English) A lower-class person living on or along a river. 3 (context chiefly pejorative English) A poker player that wins a Texas Hold'em hand by making the winning hand on the river card.

The River Rat is a river in the county of Suffolk in East Anglia, England.

Its source is near the village of Rattlesden, and is the major tributary of the River Gipping.