In culinary terms, score means to cut slits on the surface of a piece of food. The most common uses of scoring include small uniform cuts in pieces of raw meat and the deeper slashes that decorate the top of bread loves while letting steam escape.
For meat, the knife blade should penetrate only about 1/8 to 1/4 inch deep. In general, score marks should be spaced approximately 1 inch apart. From there, you can add a crosshatch pattern, insert chopped aromatics such as garlic or ginger, or press a dry seasoning rub into the little pockets.
Scoring meat before you cook it results in a greater surface area exposed to the heat, leading to more even cooking and encouraging the Maillard reaction that leads to an appealing browned crust. With tougher cuts of steak such as flank, scoring the meat severs the long fibers that make it harder to chew.
Fattier cuts of meat such as duck benefit from scoring, which allows excess fat to drain. Scoring also makes it easier for meats to absorb marinades. With whole fish, deep scores down to the bone allow heat to quickly reach the center flesh, reducing the likelihood of an overcooked exterior and undercooked interior. Scoring skin-on fish fillets keep them from curling; a few minutes in the freezer makes it easier to control the depth of your cuts for softer fish such as sole. A spiral-cut ham, sometimes marketed as a holiday ham or a city ham, displays a more extreme example of scoring, which cuts the meat through to the bone for easier serving.
Use a sharp knife when you score meat for a clean cut; dull knives, besides being dangerous, leave ragged edges. Start with a diagonal cut pattern, then turn the meat 90 degrees to add a crosshatch.