Restore theatre before broadcast (6)
I believe the answer is:
repair
'restore' is the definition.
(I know that restore can be written as repair)
'theatre before broadcast' is the wordplay.
'theatre' becomes 'rep' (repertory theatre).
'before' says to put letters next to each other.
'broadcast' becomes 'air' (to air on TV).
'rep'+'air'='REPAIR'
(Other definitions for repair that I've seen before include "Fix, mend" , "Travel or proceed toward some place" , "Get back into good shape" , "do some darning" , "Mend, restore to good condition" .)