(n.) One who foresees or foreknows.

Cassandra Chaldean Druid astroalchemist astrologian astromancer augur calamity howler crystal gazer divinator diviner divineress forecaster foreknower foreseer foreshower foreteller fortuneteller genethliac geomancer haruspex horoscoper horoscopist palmist predictor prefigurer presager prognosticator prophesier prophet prophet of doom prophetess psychic pythoness religious prophets seer seeress soothsayer stargazer vates weather prophet