Pivot

A fixed pin or short axis, on the end of which a wheel or other body turns.

The end of a shaft or arbor which rests and turns in a support; as, the pivot of an arbor in a watch.

Hence, figuratively: A turning point or condition; that on which important results depend; as, the pivot of an enterprise.

The officer or soldier who simply turns in his place whike the company or line moves around him in wheeling; -- called also pivot man.

To place on a pivot.