Sudden, surprise attack (6)
(Other definitions for ambush that I've seen before include "Launch attack from hiding" , "(Where enemies) lie in wait" , "Waylay" , "Wait in hiding to attack" , "Scene of lying in wait" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sudden surprise attack</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 raid that I've seen before include "Surprise police visit" , "Search by police without warning" , "Stock Exchange activity" , "Maraud" , "Rifle" .)