iridescence iri·des·cence UK/ˌɪɹ.ɪˈdɛs.əns/ uncommon noun 1. the visual property of something having a milky brightness and a play of colors from the surface Synonymsopalescence Related words Word family iridesceopalesce Broader terms brightness WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). WordNet 2.1 Copyright Princeton University. All rights reserved.