(n.) One who has preceded another in any position or office\; one whom another follows or comes after, in any office or position.

ancestor ancestors announcer antecedent antecedents ascendants avant-garde bellwether buccinator bushwhacker elders explorer fathers forebear forebears forefather forefathers foregoer forerunner front runner frontiersman fugleman grandfathers grandparents groundbreaker guide harbinger herald innovator lead runner leader messenger pathfinder patriarchs pioneer point precedent precursor predecessor predecessors progenitors prototype scout stormy petrel trailblazer trailbreaker vanguard vaunt-courier voortrekker