the sharp-pointed head that forms the piercing end of a spear.

any person, contingent, or force that leads an attack, undertaking, etc.

to act as a spearhead for

She spearheaded the drive for new members.

verb

bring , bring on , cause , direct , get the jump on , go out in front , guide , head , helm , influence , initiate , introduce , launch , motivate , move , originate , persuade , pioneer , produce , prompt , quarterback , run things , shepherd , spur , trail-blaze , advance , begin , create , develop , lead , start