Double-edged (6)
I believe the answer is:
ironic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">double-edged</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 ironic that I've seen before include "Wry, sarcastic" , "Suggesting the opposite for humorous effect" , "Wryly satirical" , "Strangely apt or inapt" , "Conveying meaning by saying its opposite" .)