A person who speaks about or announces something before it happens; a predictor or one who foretells.
From 'forespeak' + the agent suffix '-er' (one who does). Following the standard English pattern of adding '-er' to verbs to create nouns for people who perform that action.
In ancient cultures, forespeakers were often priests or oracles—people whose job was quite literally to speak about the future. We still have them today, just called meteorologists and economists.
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