Talk smack about (5)
I believe the answer is:
trash
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">talk smack about</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for trash that I've seen before include "Junk" , "Refuse; destroy" , "Worthless material to be disposed of" , "Wreck; rubbish" , "Garbage or nonsense" .)