Pivot point (4)
I believe the answer is:
axis
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pivot point</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for axis that I've seen before include "all revolves around this" , "Centre about which something turns" , "Imaginary line around which a body rotates" , "Supposed political alliance" , "Imaginary line about which a body rotates and a Dublin theatre" .)