1.4 What else does an index mean?

In anthropology, an index means the ratio of two comparable measures. Anthropologists talk about nasal indices and facial indices, for example. The facial index is obtained by dividing the length of the face by its breadth and multiplying the quotient by one hundred. The facial index of your teacher is:

In mathematics, an index is a superscript or subscript to a quantity (usually expressed by a letter), either in the shape of a letter, numerical value or comma (x ^{n; 2; '} ).

In physics, an index refers to a pointer, a sign that makes it easier to read a scale.

The Catholic Church's list of banned books is also known as an index (Index Librorum Prohibitorum).

Next lesson: A brief history of indices