Opposite words for procession:
backwash, turnabout, turnaround, reverse, retreat, regress, reversal, recess, return, retraction, recession, regression, ebb, reflux, retrogression, about-face.
Usage samples:
  1. The procession had formed in the body of the church, and at the head of it, in the doorway, were Indians bearing the cross.
    "Incidents of Travel in Yucatan, Vol. I.", John L. Stephens.
  2. They did not now care anything about the procession, or the coach with six horses, or the handsome ladies, or the noble gentlemen that Jerome had promised they should see.
    "The Peasant and the Prince", Harriet Martineau.
  3. There's no procession ...
    "The Return of Peter Grimm", David Belasco Edited by Montrose J. Moses.
  4. I thought you might have gone to see the procession and hear the music.
    "The Revolution in Tanner's Lane", Mark Rutherford.