/ Thesaurus / P Synonyms of protomammal Find synonyms for: Noun1. therapsid, protomammal, synapsid, synapsid reptileusage: probably warm-blooded; considered direct ancestor of mammalsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: entomology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language