spearhead

The sharpened head of a spear.

The leading forces in a military thrust.

The driving force in a given action, endeavor, or movement.

To be the leader of (a movement, for example).

The head of a spear.

The pointed head, or end, of a spear.

The pointed head, or end, of a spear.

One who leads or initiates an activity (such as an attack or a campaign).

The leading military unit in an attack.