index Definition

  • 1an alphabetical list of names, subjects, etc. with reference to the places where they occur, typically found at the end of a book
  • 2a number or ratio that represents a property or quantity's relation to another property or quantity
  • 3a statistical measure of the change in an economy or a stock market

Using index: Examples

Take a moment to familiarize yourself with how "index" can be used in various situations through the following examples!

  • Example

    I found the term in the index at the back of the book.

  • Example

    The consumer price index rose by 2% last year.

  • Example

    The Dow Jones Industrial Average is an index of 30 major American companies.

  • Example

    The index finger is usually the most dexterous and sensitive of the fingers.

index Synonyms and Antonyms

Synonyms for index

Antonyms for index

Idioms Using index

  • to be excluded from a list or catalog


    The product was taken off the index due to safety concerns.

  • to add something to a list or catalog


    The library put the new book on the index of recommended reads.

  • to wear a ring on the index finger, typically the finger next to the thumb


    She proudly wore her wedding ring on her index finger.

Phrases with index

  • a small card with lines on which information can be written


    I wrote down her phone number on an index card.

  • the level of concern a physician has for a particular disease or condition based on the patient's symptoms and medical history


    The doctor had a high index of suspicion for cancer given the patient's family history.

  • cost-of-living index

    a measure of the changes in the cost of basic necessities such as food, housing, and clothing over time


    The cost-of-living index in this city is higher than the national average.

Origins of index

from Latin 'indicare', meaning 'to point out'


Summary: index in Brief

The term 'index' [ˈɪndeks] refers to a list of names or subjects with references to their locations, a numerical or statistical measure of a property's relation to another, or a statistical measure of economic or stock market changes. Examples include 'I found the term in the index at the back of the book,' and 'The consumer price index rose by 2% last year.' Phrases like 'index card' and idioms like 'to put something on the index' extend its usage.

How do native speakers use this expression?