System of communication (8)
I believe the answer is:
language
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">system of communication</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 language that I've seen before include "speech?" , "Means of communication" , "Tongue" , "Irish, English, French, for instance" , "See 23" .)