It is related to the answers or predictions that come from a divinity, it can be the same word or prophecy, the place where it is consulted, or the person who serves as a means to convey the message. By extension of this last meaning it is also said of someone with great wisdom and who imparts his knowledge. It comes from the Latin oraculum, formed by the verb orare ("to speak, sometimes to pray") with the suffix -culum castellanizado, which in this case would not be a diminutive but an instrumentalizer.
* Only one "like" per meaning and day, the more "likes" the meaning will appear higher in the list