Commit perjury (3)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">commit perjury</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 lie that I've seen before include "Assume a horizontal position" , "Piece of fiction" , "Mistruth" , "Fabrication" , "Be prone - misrepresent the facts" .)