verb · to take the lead or coordinate a collective operation, project, or task

该项目由环保部门牵头，多个专家组共同参与。

verb · to lead an animal by the head

这项重大的科研项目由我们学校牵头实施。

verb · to act as a go-between or mediator, particularly in matchmaking or negotiations

他在中间这么一牵头，两家人的误会就解开了。