Axis (5)
I believe the answer is:
pivot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">axis</span>' is the definition.<br/ ><span class="explanation-format__explanation">(pivot is a kind of axis)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for pivot that I've seen before include "Central point around which mechanism moves" , "Fulcrum" , "Key figure" , "On which one turns" , "Central shaft" .)