Hunt and Truss mostly broadcast lies (8)
I believe the answer is:
untruths
'lies' is the definition.
(I've seen this before)
'hunt and truss mostly broadcast' is the wordplay.
'and' says to put letters next to each other.
'mostly' means to remove the last letter (most but not all of the word).
'broadcast' is an anagram indicator (letters scattered or cast around).
'truss' with its final letter removed is 'trus'.
'hunt' put after 'trus' is 'trushunt'.
'trushunt' is an anagram of 'UNTRUTHS'.
(Other definitions for untruths that I've seen before include "Lies" , "Falsehoods" , "Stories" .)