/ Thesaurus / S Synonyms of slack suit Find synonyms for: Noun1. slack suit, suit, suit of clothesusage: casual dress consisting of slacks and matching jacketWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language