Lake District hill (4)
I believe the answer is:
fell
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">lake district hill</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 fell that I've seen before include "As Jack came down" , "unloveable doctor" , "Cause to tumble down < hill" , "Cut down; hill" , "yielded to attack" .)