/ Thesaurus / S Synonyms of subject matter Find synonyms for: Noun1. message, content, subject matter, substance, communicationusage: what a communication that is about something is aboutWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: denizen Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language