A precursor or harbinger, a warning ahead.
By extension, a non-competitor who leads out the competitors on to the circuit, or who runs/rides the course prior to competitor trials, usually testing or checking the way.
A postage stamp used in the time before a region or area issues stamps of its own.
A runner at the front or ahead.
A forebear, an ancestor, a predecessor.
Something which portends or is perceived to portend either a good or evil event or circumstance in the future, or which causes a foreboding; a portent or augury.
A thing of prophetic significance.
To divine or predict from omens.
To be an omen of.