What is the meaning of omen?

noun

• A strategically located monarchy on the southern and eastern coasts of the Arabian Peninsula; the economy is dominated by oil.
  • synonyms: Oman, Sultanate of Oman, Muscat and Oman
• A sign of something about to happen.
  • usage: "he looked for an omen before going into battle"
  • synonyms: portent, presage, prognostic, prognostication, prodigy

verb

• Indicate by signs.
  • usage: "These signs bode bad news"
  • synonyms: bode, portend, auspicate, prognosticate, presage, betoken, foreshadow, augur, foretell, prefigure, forecast, predict