Synonyms for Omen (same or very similar meaning)
WordNet sense 1 (a sign of something about to happen):
portent, presage, prodigy, prognostic, prognostication
WordNet sense 2 (indicate by signs):
augur, betoken, bode, forecast, foreshadow, foretell, portend, predict, prefigure, prognosticate, auspicate
From the ODE community, based on WordNet
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