A prophet was someone who spoke or wrote prophecies.
There were several prophets in the Bible. (DS9: "Far Beyond the Stars")
In the song "Abdul Abulbul Amir", the title character was described as being one of several "sons of the prophet". (TNG: "Brothers")
In 2257 of the mirror universe, Sarek was called "The Prophet" by the leader of the Rebellion, Voq the Fire Wolf. In his position, Sarek would use his mind melding abilities to see if there was peace in people's heart. (DIS: "The Wolf Inside")
In 2367, the impostor masquerading as Ardra told Acost Jared and the other Ventaxians not to "talk like some ancient prophet around me, with thees and thous and most powerful ones". (TNG: "Devil's Due")
In 2377, upon The Doctor's expression of disinterest in being worshiped by other holograms as the central focus of a new religion, Iden told him, "Prophets are chosen, doctor. It's a blessing and a burden." (VOY: "Flesh and Blood")