An ounce is a unit of measurement used to weigh things, abbreviated as “oz.” In the United States, sixteen ounces equal one pound. A slice of bread weighs about one ounce, and a can of soda typically holds twelve fluid ounces.

Over centuries, different countries developed their own versions of the ounce. Today, most of the world uses the metric system (grams and kilograms), but Americans still use ounces for many everyday measurements. When you buy deli meat, it might be sold by the ounce. When you check a recipe, butter might be measured in ounces.

People also use “ounce” figuratively to mean a small amount of something: “If someone had an ounce of sense, they would bring an umbrella.” This suggests that even a tiny bit would make a difference, just as an ounce is a small but measurable quantity.