unnotify

verb2

1. •
   (rare) To cancel (a notification).

   • July 3, 1757, Horace Walpole, letter to Sir Horace Mann I notified to you the settlement of the Ministry, and, contrary to late custom, have not to unnotify it again. However, it took ten days to complete, after an inter-ministerium of exactly three months.
2. •
   (rare) To notify (a person) that a prior notification should now be disregarded.

   • "Well, you unnotify the railroad," Mugivan stormed. — 1950