2. (noun)index, index number, indicant, indicator a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time
3. (noun)exponent, power, index a mathematical notation indicating the number of times a quantity is multiplied by itself
4. (noun)index an alphabetical listing of names and topics along with pagenumbers where they are discussed
5. (noun)index, index finger, forefinger the finger next to the thumb