Definitions
1.NounThe pointed head, or end, of a spear.
2.NounOne who leads or initiates an activity (such as an attack or a campaign).
3.NounThe leading military unit in an attack.
4.NounA player who initiates attacking moves.
5.VerbTo drive or campaign ardently for (an effort, project, etc.); to direct."He spearheaded the entire project from day one."