Seize suddenly (6)
I believe the answer is:
snatch
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">seize suddenly</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 snatch that I've seen before include "Grab - wrench" , "Seize quickly, grab" , "bag" , "pull" , "Deftly seize" .)