Fulcrum; turn (5)
I believe the answer is:
pivot
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fulcrum</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">turn</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that pivot is a type of turn)</span><br/ ><br/ ></span>
(Other definitions for pivot that I've seen before include "Central point on which things turn" , "Central point around which mechanism moves" , "Key figure" , "Turning pin" , "Centre point" .)