With regards to conference realignment, Grant of Rights (GOR) means that schools have signed their media rights to the conference for a period of time.
Taking the most recent B12 contract as an example, their deal includes a "grant of rights" agreement. This means if a Big 12 school leaves for another league in the next 13 years, that school's media rights, including revenue, would remain with the Big 12 and not its new conference.