crystal ball

plural crystal balls

1. A globe of glass or crystal that is used to foretell the future.

   The psychic looked into the crystal ball and saw into the future.

   2 more examples

   "Well, Victor agreed and Madame Rosita sat down with her crystal ball on a black cloth in front of her."

   1957, Sydney J. Bounds, The Robot Brains, London: Digit Books, page 31

   The object that he found most interesting was a large crystal ball standing in the middle of the table. “Ah!” he said. “’Tis a giant scrying glass! Like a full moon! I feel its power!”

   1970, Richard Carpenter, Catweazle, Harmondsworth: Puffin Books, page 85

   Synonyms: crystal sphere, orbuculum, seeing stone, shew stone, showstone, scrying stone

2. broadlyfigurativelyA manner or method of seeing into the future.

   If her past is a crystal ball to her future, she will perhaps never be rich, even though she is a kind, hard-working person.

3. One of the magickal tools of Wicca, used for divination and altar purposes.