What is another word for "pioneer"?

Roget's Thesaurus (1911) lists these synonyms for "pioneer": abecedarian, advance, advanced, adviser, ahead, antecedent, anterior, anteriority, apostle, avant-courier, beak, bear, before, bellwether, bend, bow, brow, chalk, clergy, coach, coin, come, confront, countenance, crammer, dame, dawn, director, disc, disciplinarian, disk, divine, dominie, don, dry, duenna, est, example, exordium, expositor.