Insider's lingo (5)
I believe the answer is:
argot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">insider's lingo</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for argot that I've seen before include "Patois, vernacular" , "Jargon - patois" , "Special language of a groat?" , "Groat (anag)" , "Ancient Greek coin" .)