Definitions of skim:

• noun:   reading or glancing through quickly
• noun:   a thin layer covering the surface of a liquid

  Example: "There was a thin skim of oil on the water"

• verb:   read superficially
• verb:   remove from the surface

  Example: "Skim cream from the surface of milk"

• verb:   coat (a liquid) with a layer
• verb:   cause to skip over a surface
• verb:   examine hastily
• verb:   move or pass swiftly and lightly over the surface of
• verb:   travel on the surface of water
• adjective:   used of milk and milk products from which the cream has been removed

  Example: "Yogurt made with skim milk"