reversing

1. To turn something around so that it faces the opposite direction or runs in the opposite sequence.

   to reverse a portion of video footage

2. To turn something inside out or upside down.
3. To transpose the positions of two things.
4. To change totally; to alter to the opposite.
5. To return, come back.
6. To turn away; to cause to depart.
7. To cause to return; to recall.
8. To revoke a law, or to change a decision into its opposite.

   to reverse a judgment, sentence, or decree

9. To cause a mechanism or a vehicle to operate or move in the opposite direction to normal.
10. To change the direction of a reaction such that the products become the reactants and vice-versa.
11. To place a set of points in the reverse position
12. (of points) to move from the normal position to the reverse position
13. To overthrow; to subvert.

noun

An act of reversal.