/ Thesaurus / S Synonyms of supergrass Find synonyms for: Noun1. supergrass, grass, informer, betrayer, rat, squealer, blabberusage: a police informer who implicates many peopleWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language