Backchat (3)
I believe the answer is:
lip
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">backchat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in other clues)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for lip that I've seen before include "Part of mouth or cheek" , "Sauce" , "Edge; impudence" , "Edge, rim" , "Top edge of a vessel" .)