An endorsement of something or someone, as in Our candidate doesn't have the governor's seal of approval , or The new management gave the old refund policy their seal of approval . This idiom was used, and perhaps invented, as an advertising gimmick of Good Housekeeping Magazine , which gave its so-called “seal of approval” to products it endorsed; the products' packaging in turn bore a small emblem attesting to this endorsement. The noun seal here is used in the same sense as in set one's seal on