Bush telegraph (9)
I believe the answer is:
grapevine
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bush telegraph</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for grapevine that I've seen before include "Informal source of information" , "News source" , "source of rumour" , "Private source of information" , "(Informal) means of spreading information?" .)