spearhead
n. C1 Advanced US //ˈspɪɹˌhɛd// UK //spˈiəhɛd// spear·head
n. the person or thing that leads a movement or an attack. It is the most important part of a group that is doing something big.
n. the leading part of a movement, attack, or organization. Often used metaphorically to describe the person or entity that drives a particular initiative forward.
She is the spearhead of the new environmental campaign.
The new CEO became the spearhead of the company's digital transformation, leading the charge into artificial intelligence.
As the spearhead of the diplomatic effort, the ambassador worked tirelessly to bridge the gap between the two nations before the summit began.
From Middle English spere-hed; equivalent to spear + head.