-mancy, -mancer, -mantic, -mantical
(Greek: used as a suffix; divination, prophecy, fortune telling; to interpret signs so “practical” decisions can be made [related to -mania])
It isn't so much the things we don't know that gets us into trouble. It's the things we know that aren't so.
If you keep on saying things are going to be bad, you have a good chance of being a prophet.
Chronomancy was formerly practiced especially in China.
It also regulated the words to be used on particular occasions. Cicero stated that the Pythagoreans were very attentive to these presages, and according to Pausanius, it was a favorite method of divination at Smyrna, where the oracles of Apollo were interpreted.
The onion which sprouted most rapidly indicated that the person whose name had been inscribed on it was enjoying vigorous health.
Another application was that wishes would come true if one burnt onion skins on a fire. Sometimes the onions had to be placed on the altar at Christmas before they had any divine significance.

Sometimes people wonder if this is the same system that is being used by modern weather forecasters to predict current weather conditions.
The “wheel-of-fortune” found at carnivals or on the TV “Wheel of Fortune” are based on this concept. Cyclomancy has survived in various parlor games; such as, “spin the bottle”.
Cross references of word families that are related directly, or indirectly, to: "divination, diviner; seer, soothsayer, prophecy, prophesy, prophet": augur-; auspic-; fa-, fate; Fates in action; futur-; omen; -phemia; sorc-, sorcery; vati-.
A cross reference of other word family units that are related directly, or indirectly, to: "chance, luck, fate": aleato-; auspic-; cad-; fortu-; serendipity; sorc; temer-; tycho-.