You searched for: “retromancy
retromancy (s) (noun) (no pl)
Divination by things seen over one’s shoulder: Believing in retromancy, Jack said, "Tom, don't look back over your shoulder because a bad omen might be prophesied!"
This entry is located in the following units: -mancy, -mancer, -mantic, -mantical (page 13) retro-, retr- (page 2)