rebroadcast

As a noun playback

is the replaying of previously recorded sound or moving images.

As a verb rebroadcast is

broadcast again.

As verbs the difference between rerun and rebroadcast

is that rerun is to run (a previously broadcast television program) again while rebroadcast is broadcast again.

As a noun rerun

is (american) a television program shown after its initial presentation — particularly many weeks after its initial presentation; a repeat.

As verbs the difference between retransmitting and rebroadcast

is that retransmitting is while rebroadcast is broadcast again.