Mention a broadcast about arrest (3)
I believe the answer is:
nab
'arrest' is the definition.
(synonyms)
'mention a broadcast about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'NAB' is hidden within 'mention a broadcast'.
(Other definitions for nab that I've seen before include "Take" , "Catch (thief) (colloq.)" , "Capture, catch" , "Seize quickly" , "Catch; grab suddenly" .)