noun
lead-off batter; first batter in the lineup
Baseball term for the first batter in the batting order, who leads off the game or an inning.
彼はチームの先頭打者として初球を打った。
He hit the first pitch as the team's lead-off batter.
先頭打者が出塁すると、得点のチャンスが広がる。
When the lead-off batter gets on base, scoring chances increase.
Also means the first batter in the lineup, but 先頭打者 emphasizes the role of leading off an inning or game, while 一番打者 simply refers to the first spot in the batting order.
Compound of 先頭 (lead, head) and 打者 (batter), directly describing the batter who leads off.