|a stone or substance thought by alchemists to be capable of transmuting base metals into gold|
|the offspring of a zebra and a donkey.|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
The stone or material that practitioners of alchemy believed capable of changing other metals into gold.
Note: Figuratively, the “philosopher's stone” is a substance thought to be capable of regenerating man spiritually.