On American forms, Caucasian is often a box you tick to mean a white person: someone with pale skin, usually of European family background. That is the meaning you will meet in the US, in police talk, and in older textbooks. Though actually it is a messy word, and scientists do not use it this way any more. It comes from the Caucasus, the mountains between the Black Sea and the Caspian Sea. A German doctor in the 1700s, Blumenbach, put white people in a group he named Caucasian because he believed the first humans, or the most beautiful skulls, came from there. That story is not science now. People who really live in the Caucasus — Georgians, Armenians, Chechens, and many others — are Caucasian in the geographic sense, and they are not one race, and they are not what a US form means by that tick-box. In Britain people more often just say white. In careful talk, many prefer white too, because Caucasian pretends to be a scientific race name when it is not. There is also a joke sense: in the film The Big Lebowski, a White Russian cocktail is called a Caucasian. That is a drink, not a person.