To rebroadcast something is to make it available again on the radio, television, or online. During a weather emergency, like a hurricane, local TV stations usually rebroadcast news reports throughout the day.
Use rebroadcast as a verb, meaning "play again," or a noun, for the actual show or program. You might miss an exciting basketball game, but you'll probably be able to watch a rebroadcast the next day. The word rebroadcast combines the "again" prefix re- and broadcast, which started out with a very different definition — it meant "spread seeds." The modern meaning dates from the 1920s, when it referred to radio.