noun
fielder
Baseball term for any defensive player, including infielders and outfielders. Contrasts with 投手 (pitcher).
彼は高校時代、野手として活躍した。
He played an active role as a fielder in high school.
野手の守備位置を確認する。
Check the fielders' defensive positions.
外野手 is a specific type of fielder (outfielder), whereas 野手 is the general term for any fielder.
Compound of 野 (field) and 手 (player), literally 'field player'. A straightforward baseball term.