means A person, place, or source believed to deliver wise or prophetic answers, especially one regarded as an infallible authority.

from From Latin oraculum, a divine pronouncement or the shrine where you'd go to get one, built on orare, 'to speak' or 'to plead' (the same root that gives us 'orator' and 'oration'). The original oracles were sacred sites like Delphi, where a priestess spoke for the god — so the word carries, at its core, the act of speaking, and the assumption that someone divine is doing the talking.