ph.

1. 退学;退出(比赛等)
If someone drops out of college or a race, for example, they leave it without finishing what they started.

2. 拒绝接受传统规范;离经叛道;摈弃社会习俗
If someone drops out, they reject the accepted ways of society and live outside the usual system.

1. give up in the face of defeat of lacking hope
admit defeat

e.g. In the second round, the challenger gave up

Synonym: give upfall by the waysidedrop by the waysidethrow inthrow in the towelquitchuck up the sponge

2. leave school or an educational program prematurely

e.g. Many students drop out because they are not prepared for our challenging program

3. withdraw from established society, especially because of disillusion with conventional values

e.g. She hasn't heard from her brother in years--he dropped out after moving to California