Breadcrumb Home > Thesaurus > O Synonyms of opsin Find synonyms for: Noun1. opsin, proteinusage: retinal protein formed by the action of light on rhodopsinWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of opsin (Dictionary) ✖ Related Content Daily Word Quiz: sophism Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language