Attack from concealment (6)
I believe the answer is:
ambush
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">attack from concealment</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 ambush that I've seen before include "An attack launched from hiding" , "Egyptian cross" , "Scene of lying in wait" , "Weakening" , "Attack from concealment" .)