A leader or guide who leads a group or movement; someone who takes the lead and shows direction.
彼女は新しいプロジェクトの先導者としてメンバーをまとめた。
She organized the members as the leader of the new project.
社会改革の先導者たちが集会で意見を述べた。
The leaders of the social reform movement expressed their opinions at the meeting.
山道では先導者の指示に従って歩いてください。
On the mountain trail, please follow the leader's instructions.