›[S]a thin surface layer that develops on something because of use, age, or chemical action: His tomb was covered with a yellow patina of lichen.Coverings and layers›[S]formalsomething that makes someone or something seem to be something that they are not: Beware their patina of civility, it's only an act.Hiding and disguising›[U]specializeda blue-green layer that forms on copper, brass or bronzeCoverings and layers