The act of going before, or forward.
- The act or state of preceding; precedence.
- Physics The motion of the axis of a spinning body, such as the wobble of a spinning top, when there is an external force acting on the axis.
- Astronomy Precession of the equinoxes.
- Astronomy A slow gyration of the earth's axis around the pole of the ecliptic, caused mainly by the gravitational pull of the sun, moon, and other planets on the earth's equatorial bulge.