Put up a fight
I believe the answer is:
resist
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">put up a fight</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for resist that I've seen before include "Sister (anag)" , "Hold out for sister" , "Forgo" , "turn down" , "Oppose or fight against someone" .)