forerunner

Meanings

1. A runner at the front or ahead.
2. 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.
3. A precursor or harbinger, a warning ahead.
4. A forebear, an ancestor, a predecessor.
5. A postage stamp used in the time before a region or area issues stamps of its own.

Etymology

From Middle English forrenner, foreriner. Calque of Latin praecursor (“one who runs before, a forerunner”). Equivalent to fore- + runner and/or forerun + -er.