What is another word for precession?

There isn't a single perfect synonym for "precession," as the word has different meanings depending on the context. Here are some possible alternatives, depending on what you mean:

For the astronomical meaning:

* Gyroscopic drift: This refers to the slow, conical motion of a spinning object's axis of rotation.

* Axial precession: This specifically describes the gradual shift in the Earth's axis of rotation.

* Precessional motion: This is a more general term for any type of precession.

For the general meaning of "preceding" or "coming before":

* Antecedent: This refers to something that precedes something else in time or order.

* Prior: This is a general term for something that comes before something else.

* Previous: This refers to something that happened or existed before the present time.

* Foregoing: This refers to something that has been mentioned or discussed previously.

To provide a more accurate synonym, please provide more context about how you're using the word "precession."