to choose the best people or things from a group

They're worried the new school will skim off the brightest students, leaving the public school to teach the problem kids. 他们担心那所新学校会把最聪明的学生拉走，让公立学校处理有问题的学生。

to secretly take money that is in your care or that belongs to an organization or business you work for

He got caught skimming off funds from the charity. 他被发现从慈善机构窃取钱财。