Seize power (5)
I believe the answer is:
usurp
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">seize power</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 usurp that I've seen before include "Oust" , "Assume authority" , "Take power unlawfully" , "Take over - misappropriate" , "Appropriate without authority" .)