打線 (dasen) means “batting lineup” | MotiTan Japanese Dictionary

More examples

若手選手の加入で、打線に厚みが出ました。waka te sen shu no ka nyū de da sen ni atsu mi ga de ma shi ta

The addition of young players gave the batting lineup more depth.

打線 (dasen) presents a team's batters as a coordinated line whose results create its offensive threat.

打順dajun: The order in which a team's batters come to the plate.
打撃陣dagekijin: The group of players who bat for a team.

野球で、打者が打順どおりに連なる攻撃陣。また、攻撃陣の打撃の強さ。ya kyū de da sha ga da jun dō ri ni tsura na ru kō geki jin ma ta kō geki jin no da geki no tsuyo sa

The word 打線 (dasen) joins 打 (da, "hit") with 線 (sen, "line") to name the ordered line of hitters in a baseball team.

A Japanese team may be praised for a 厚い打線 (atsui dasen) when many places in its batting order are capable of producing runs, not only its best hitter.