The definition of a cookie sheet is a baking tool consisting of a relatively flat piece of material (usually metal and often with handles) onto which cookies and other items are placed to be cooked in the oven.
An example of a cookie sheet is the silver tray on which you bake your chocolate chip cookies in the oven.
Cookie-sheet Sentence Examples
Add another cookie sheet to the top to help press more moisture out of the paper (do this outside or in the bathtub).
When people think of sheet cakes, they often think of the large, Texas-style sheet cake that's actually prepared in a cookie sheet rather than a cake pan.
Spray a cookie sheet with non-stick spray, and then place all your worms on the baking sheet.
Pre-heat your oven to 350°, and grease a cookie sheet with non-stick spray.