License

1. Official or legal permission to do or own a specified thing. Proof of permission granted, usually in the form of a document, card, plate, or tag: a driver's license. Every dog must have a license.
2. Deviation from normal rules, practices, or methods in order to achieve a certain end or effect. The writer has exercised poetic license in that book.
3. Lack of due restraint; excessive freedom. When liberty becomes license, dictatorship is near.