/ Thesaurus / B Synonyms of black rat Find synonyms for: Noun1. black rat, roof rat, Rattus rattus, ratusage: common household pest originally from Asia that has spread worldwideWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language