名詞 drop out:

1. someone who quits school before graduation
   同義詞：dropout
2. someone who withdraws from a social group or environment
   同義詞：dropout

動詞 drop out:

1. give up in the face of defeat of lacking hope; admit defeat
   同義詞：give up, fall by the wayside, drop by the wayside, throw in, throw in the towel, quit, chuck up the sponge
2. leave school or an educational program prematurely

1. Some old women and men grow bitter with age; the more their teeth drop out, the more biting they get.
   有些老太婆與老頭子，隨著年歲而變得脾氣暴戾——牙齒掉得越多，越發(fā)咬得入骨。
2. In any year some of the students on this crash course find the pace too hot for them and drop out before Christmas.
   每年都有一些修這門速成課的學生覺得課程負擔太重而于圣誕節(jié)前輟學的。
3. He drop out because of the pressure.
   由于校規(guī)很嚴，所以他退學了。
4. The marathon runner raced ahead in the early stages of the race but he had overplayed his hand and had to drop out exhausted with only three miles to go.
   這位馬拉松賽跑者在比賽的開始階段跑在前面，但他過高地估計了自己的力量，結果在離終點僅３英里時，跑得筋疲力盡力而不得不退出比賽。