n. a line that marks the side boundary of a playing field
n. an auxiliary line of merchandise
v. remove from the center of activity or attention; place into an inferior position
n. 副业, 旁线, 界线, 兼职, 旁观者看法
vt. 使退出比赛场地
1. She decided to start a sideline business selling handmade crafts.
她决定开始一个副业，出售手工艺品。
2. Many athletes have sideline jobs to earn extra money.
许多运动员有副业来赚取额外的钱。
3. He was injured during the game and had to watch from the sideline.
他在比赛中受伤，只能在场边观看。