THESAURUS
groundbreaker
ancestor, announcer, antecedent, avant-garde, bellwether, buccinator, bushwhacker, explorer, forebear, foregoer, forerunner, front runner, frontiersman, fugleman, guide, harbinger, herald, innovator, lead runner, leader, messenger, pathfinder, pioneer, point, precedent, precursor, predecessor, scout, stormy petrel, trailblazer, trailbreaker, vanguard, vaunt-courier, voortrekker