Cut or knock down (4)
I believe the answer is:
fell
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">cut</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(felling is a kind of cutting)</span><br/ ><br/ >'<span class="explanation-format__original">knock down</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for fell that I've seen before include "Collapsed; hill" , "Came down - cut down" , "Cut down (tree), dropped" , "'I do not like thee Doctor ....'" , "Lake District hill" .)