0 a person or group of people that is the first to do something considered difficult or dangerous, especially a group of soldiers, etc. who are the first to enter a battle area:
Aircraft carriers and their battle groups have served as the leading edge of the US military - "the tip of the spear," as the admirals like to say.
He has been the self-appointed tip of the spear in the fight against illegal immigration.
"Artists need to be the tip of the spear in this new digital world we are moving into," he says.
Feeding troops at the tip of the spear remains one of the most difficult tasks for the US war machine.
The unit is at the tip of the spear in a new plan to quell violence in the city.