/ Thesaurus / P Synonyms of protohemin Find synonyms for: Noun1. hemin, protohemin, chlorideusage: a reddish-brown chloride of heme; produced from hemoglobin in laboratory tests for the presence of bloodWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language