index - noun

a numerical scale used to compare variables with one another or with some reference number

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

a mathematical notation indicating the number of times a quantity is multiplied by itself

an alphabetical listing of names and topics along with page numbers where they are discussed

the finger next to the thumb

index - verb

• list in an index
• provide with an index
• adjust through indexation

index - thesaurus

exponent   forefinger   indicant   indicator   power