( formal )
1.
to return to a former state; to start doing sth again that you used to do in the past :
After her divorce she reverted to her maiden name.
His manner seems to have reverted to normal.
Try not to revert to your old eating habits.
2.
to return to an earlier topic or subject :
So, to revert to your earlier question ...
The conversation kept reverting to the events of March 6th.