omen Definition

1. A circumstance, phenomenon, etc that is regarded as a sign of a future event, either good or evil.

Thesaurus: sign, premonition, warning, portent, augury, indication, the writing on the wall.
2. Threatening or prophetic character.

Example: bird of ill omen

omened, omening
1. To portend.

Note: in compounds
With omens of a specified kind. See also ominous.
Example: ill-omened