backstop
noun [ C ] uk/ˈbæk.stɒp/ us/ˈbæk.stɑːp/
(PLAYER)
（英国圆场棒球运动中的）接手
(in rounders) a player who stands directly behind the player from the opposing team who is trying to hit the ball, and attempts to catch the ball after it has been thrown if the person does not hit it
US（棒球）接手（catcher的非正式说法）
informal for catcher
(FENCE)
（棒球场上的）挡球网
(in baseball) a high fence behind the player hitting the ball, that prevents balls from leaving the playing area if they are not hit or caught