pivot

pivot is a Noun

Definition:

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

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

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

[4] The officer or soldier who simply turns in his place whike the company or line moves around him in wheeling; -- called also pivot man. Pivot bridge, a form of drawbridge in which one span, called the pivot span, turns about a central vertical axis. -- Pivot gun, a gun mounted on a pivot or revolving carriage, so as to turn in any direction. -- Pivot tooth (Dentistry), an artificial crown attached to the root of a natural tooth by a pin or peg.