/ Thesaurus / S Synonyms of sewer rat Find synonyms for: Noun1. sewer rat, brown rat, Norway rat, Rattus norvegicususage: brown rat commonly found in sewersWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: illegible Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language