1) n. governmental permission to perform a particular act (like getting married), conduct a particular business or occupation, operate machinery or vehicles after proving ability to do so safely or use property for a certain purpose. 2) n. the certificate that proves one has been granted authority to do something under governmental license. 3) n. a private grant of right to use real property for a particular purpose, such as putting on a concert. 4) n. a private grant of the right to use some intellectual property such as a patent or musical composition. 5) v. to grant permission by governmental authority or private agreement.