What is another word for "scout"?

Roget's Thesaurus (1911) lists these synonyms for "scout": about, advance, advanced, ahead, ambassador, anterior, anteriority, apparitor, aside, away, bag, beak, bearer, before, bellman, bend, bow, boy, brow, cable, carrier, cast, chore, chosen, coin, come, commissionaire, confront, correspondent, countenance, courier, crier, dak, declination, decline, delivery, deny, diplomatist, disc, discard.