green·back·er \ˈgrēnˌbakə(r)\noun Etymology:greenback (money) + -er 1.usually capitalized: a member of a post-Civil War American political party opposing any reduction in the amount of paper money in circulation 2.: one who advocates a paper currency backed only by the United States government < the silverites, the greenbackers, the price stabilizers, and others … are pledged to a central-bank scheme — Harper's >