Broadcast Dens composition (4)
I believe the answer is:
send
'broadcast' is the definition.
(I know that broadcast can be written as send)
'dens composition' is the wordplay.
'composition' indicates an anagram (letters arranged or composed in a different order).
'dens' anagrammed gives 'SEND'.
(Other definitions for send that I've seen before include "Dispatch by post" , "Despatch, remit" , "Consign" , "and 2: Advise" , "broadcast" .)