指数

Noun

 * 1)  index - a single number calculated from an array of prices or of quantities.
 * 2)  exponent, power - a product of equal factors. Notation and usage: xn, read as "x to the power of " or "x to the th power", denotes x &times; x &times; ... &times; x, in which x appears  times, where  is called the exponent; the definition is extended to non-integer and complex exponents.