Formal discussion through argument (6)
I believe the answer is:
debate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">formal discussion through argument</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for debate that I've seen before include "Discuss through argument" , "Verbal disputation" , "Public discussion, perhaps a contest" , "Discussion with arguments for and against" , "A public discussion about a topic" .)