Lingo or jargon (5)
I believe the answer is:
argot
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">lingo</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">jargon</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for argot that I've seen before include "Talk of thieves" , "Particular group's jargon" , "Slang, patois" , "Slang for a groat (5)" , "manner of speaking" .)