drop out
phrasal verb with drop verb uk/drɒp/ us/drɑːp/ -pp-
停止;退出;中断
to not do something that you were going to do, or to stop doing something before you have completely finished
He dropped out of the race after two laps. 在跑了两圈后他退出了比赛。
退学，辍学
If a student drops out, they stop going to classes before they have finished their course.