v.1. To remove some floating matter from a liquid: They use a net to skim the cranberries off the surface. They skim off the dross before pouring the metal into molds.
2. To appropriate some money illegally or dishonestly: The dictator skimmed off over $1 million from international donations and deposited it in personal bank accounts. The company was skimming money off its employees' paychecks and using it to cover losses.