せんとう先頭sentou
1.

The foremost position in a line or group, often representative of leadership or initiative in an endeavor or movement.

2.

The very front of an organized gathering or procession, indicating a role in guiding or directing others.

3.

The leading edge in a competitive context, such as sports or political actions, where one takes the initiative or is the first to advance a particular agenda.

Example:

さあ出発しよう。君先頭を行きなさい。

せんとうだしゃ先頭打者sentoudasha
1.

The player who bats first in the lineup, tasked with setting the tone for the game and often possessing skills in getting on base.

2.

A key offensive position in baseball, representing the starting point of the batting order, typically known for speed and on-base ability.

3.

The individual who faces the pitcher at the beginning of an inning, often responsible for creating opportunities for subsequent batters by reaching base.

Example:

先頭打者がヒットで出塁した。

せんとうしゅうだん先頭集団sentoushuudan
1.

A group of individuals positioned at the forefront during a race or competition, typically consisting of those with the fastest pace.

2.

The segment of participants in a race that is ahead of the majority, often vying for top placements.

3.

A collective of front-runners that represents the strongest contenders in a particular event or context.

せんとうぶたい先頭部隊sentoubutai
1.

A group of soldiers designated to be the first to engage in combat or secure an area, often tasked with reconnaissance or establishing a foothold ahead of the main forces.

2.

The foremost segment of a military unit that spearheads an operation, typically focusing on innovative tactics and strategies in the early stages of an engagement.

3.

A tactical element composed of elite forces that is deployed ahead of the main body to gauge enemy strength and conditions, providing crucial intelligence for coordination of subsequent forces.