掉落,掉出;退出,退學
drop out v 1: give up in the face of defeat of lacking hope; admit defeat; "In the second round, the challenger gave up" [syn: {give up}, {fall by the wayside}, {drop by the wayside}, {throw in}, {throw in the towel}, {quit}, {chuck up the sponge}] [ant: {enter}] 2: leave school or an educational program prematurely; "Many students drop out because they are not prepared for our challenging program"