ounce

An ounce is most commonly known as a small unit for measuring weight. If you buy a pound of coffee, that equals sixteen ounces. For liquids, we usually say "fluid ounce" instead, and that is used for things like perfume, medicine, or drinks. The word is also often used in a figurative way to mean a very small amount of something. You might hear that someone does not have "an ounce of patience" or has "an ounce of courage." So the word can refer to an exact measure or simply to a tiny bit of something.

The word "ounce" has two main everyday uses. First, it is a unit of weight. In the common system used in the United States, one pound equals sixteen ounces, and one ounce is about 28.35 grams. We use it for small amounts of things such as food, mail, and other light items. There is also a "troy ounce," used especially for precious metals like gold and silver, and that is slightly heavier at about 31.1 grams.

Second, in "fluid ounce," it is a unit for measuring volume, especially for liquids. That is why drink bottles, recipe books, and medicine labels often show fluid ounces rather than plain ounces. The word also has a figurative use: people say "an ounce of sense," "an ounce of kindness," or "not an ounce of fear" to mean a very small amount. Its deeper history goes back to the Latin uncia, meaning "a twelfth part." That old idea of a small part helps explain why the word still works so naturally both as a real measurement and as an image for a tiny amount.