As a noun, spearhead can literally be the point of a spear, a weapon. Figuratively a spearhead is a person or group of people that takes charge of a project or movement. The spearhead is the one who is responsible for forward motion and progress. It is used especially in sports for a person or player who is known for aggressive moves on the field or court.
As a verb, spearhead means to push something forward or lead the charge. It can be used in a military sense as well.
The oldest artifact from prehistory is an 11,200 year-old spearhead. [Columbia Daily Tribune]
Victory had a momentary scare when Carl Valeri’s pass went astray and fell to Josh Kennedy, but the City spearhead could not get the ball from under his feet to make the chance count. [Sydney Morning Herald]
They are missing two spearheads in the off-spinner Saeed Ajmal and injured pace man Junaid Khan, which severely dents their chances. [The Daily Telegraph]
The NFL Players Association’s Mackey-White Committee, which spearheads player safety initiatives, spent considerable time discussing not only the potential health benefits of helmet sensors, but also the legal and ethical pitfalls that come with them in mid-April. [FOX Sports]
In 1966, Sen. Everett Dirksen of Illinois spearheaded an aggressive campaign to add a Constitutional amendment permitting school prayer. [The New York Times]
Lafferty has netted five times in five Euro 2016 qualifiers and is spearheading the bid to make next year’s finals in France. [BBC Sports]