The crossword solution for the term 'transmission ending' is OVER, which is a four-letter word. OVER is a preposition that is used to indicate movement from one side of an object or area to the other, or to indicate a position above something else. It can also be used to indicate a period of time that has passed. In terms of transmission, it can refer to the end of a transmission, such as when a radio signal stops broadcasting or when a television program ends.