noun
heavy hitter; power hitter; slugger
Baseball term for a batter known for hitting with power, often producing extra-base hits and home runs.
彼はチームで一番の強打者だ。
He is the best power hitter on the team.
強
The pitcher threw carefully to face the slugger.
打者 is a general term for a batter in baseball, without the implication of power.
Compound of 強打 (hard hit) + 者 (person). The exact historical derivation is uncertain, but the word is transparently formed from its components.