1. Someone, or something, considered to be a source of knowledge, wisdom, or prophecy: In the fantasy story, the oracle suddenly appeared and spoke to the young man.
2. A wise or prophetic statementL One example of an oracle could be, "Do unto others as they do unto you."
3. In ancient Greece and Rome, a shrine dedicated to a particular god, or goddess: An oracle was a place where people went to consult a priest, or priestess, in times of trouble or uncertainty.

One of the most famous was the Delphic Oracle of Apollo.

4. An ancient Greek or Roman deity that a priest, or priestess, would consult for advice on behalf of troubled or uncertain people: Sharon read in her book that a oracle could be asked for guidance in trouble times.

An oracle can be a piece of advice, often in the form of a puzzle or an enigmatic statement, handed down by an ancient Greek or Roman deity.
5. A message believed to come from God in response to a request, plea, or petition: Marie was waiting anxiously for an oracle from God in response to her prayer,
6. The most sacred area in either of the Temples mentioned in the Bible: An oracle was often referred to as the Holy of Holies.