index

IN-deks/ˈɪndɛks/

Pluralindexes, indices

Verbindexes, indexing, indexed

20 meanings of index

Practice

1
where-to-find listnouncountable
An alphabetical list that shows where to find things, like topics in a book.
Like a map that tells you which page to turn to.
I checked the index at the back of the book to find the chapter on volcanoes.
The cookbook has a handy index so you can look up recipes by name.
UsageSay indexes for more than one book index.
2
measured rationouncountable
A number that measures a property or compares two amounts.
Like a score that rates one quality with a single number.
The refractive index of glass tells us how much it bends light.
The doctor said my body mass index was in the healthy range.
Similarcoefficient
Note
3
price figurenouncountable
A single number that shows how a group of prices or amounts changes over time.
Like one score that sums up a whole team's performance.
The cost-of-living index rose again last month.
Investors watched the stock market index climb all afternoon.
UsageSay the price index or a stock index.
Note
4
verbtransitive
To make an alphabetical list that shows where to find topics in a book.
Like making a map of where each topic lives in a book.
Publishers usually index a reference book before printing it.
He indexed the manuscript by chapter and topic.
Similarcatalog, list
Note
5
pointing fingernouncountable
The finger next to the thumb, used for pointing.
Like the finger you use to push a doorbell.
Hold the pencil between your thumb and index.
Guitar players often pluck with the thumb, index, and middle fingers.
UsageSay index finger.
Similarforefinger, pointer
Note
6
database search aidnouncountable
A helper structure in a database that makes searching a table much faster.
Like the tabs on a folder that help you find a file fast.
Adding an index made the search run in seconds.
The database slowed down because the table had no index.
Note
7
list positionnouncountable
A number that shows where a piece of data sits in a list or table.
Like a seat number that tells you exactly where to sit.
The program uses an index to find the right item in the list.
If the index is too large, the lookup fails.
Similarsubscript
Note
8
telling signnouncountable
A sign that shows something exists or tells you what it is like.
Like a frown that's a sign someone is upset.
A person's actions are often a clear index of their character.
Rising prices can be an index of a growing economy.
UsageSay something is an index of something else.
Similarsign, indication, indicator, measure, gauge
Note

Less common meanings

9
adjust for inflationverbtransitive
To adjust an amount of money so it keeps the same real value as prices rise.
Like raising your allowance each year so it still buys the same treats.
Many governments index pensions so they rise with the cost of living.
The contract was indexed to keep wages fair as prices climbed.
UsageSay pay is indexed to prices.
Similarlink, peg, tie
Note
10
fetch itemverbtransitive
To get a value from a list or table by using its position number.
Like finding a house by its street number.
You can index the array to find the third item.
The program indexes the list to pull out each name.
Note
11
measure indirectlyverbtransitive
To measure something by comparing it to a related value.
Researchers index a region's wealth by its average income.
Researchers indexed stress by measuring heart rate during the test.
UsageSay we index health by life span.
Similarmeasure, gauge, assess
Note
12
dial pointernouncountable
A pointer that moves across a dial or scale to show a measurement.
Like the needle on a bathroom scale that points to your weight.
Turn the knob to move the index on the barometer to today's reading.
A small index inside the thermometer marks the day's highest temperature.
Similarpointer, needle, hand
13
power (math)nouncountable
A small raised number that tells how many times to multiply a number by itself.
Like a tiny tag that says, multiply me this many times.
Write the index just above and to the right of the base number.
In two to the power of five, the index is five.
Similarexponent, power
Note
14
signalverbtransitive
To be a sign of something or point to it.
Like footprints in the snow that show someone walked by.
Linguists say the way you say 'car' can index where you grew up.
A trembling voice often indexes fear.
Similarindicate, signal, mark, signify
Note
15
nounobsolete
A short opening part that tells you what is coming in a book or play.
Ay me, what act, that roars so loud and thunders in the index?
c. 1599, William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”Here, index means the opening part that tells what is coming.
Note
16
verb
To move a part to an exact position using a machine or tool.
17
verbobsolete
To make a list of all the things in a place.
18
noun
A printed mark shaped like a hand with a pointing finger, used to point out something important.
19
noun
In math, the number of equal-sized pieces that a smaller group splits a bigger group into.
20
noun
A kind of word whose meaning changes depending on when, where, or by whom it is used.

Practice

Can you tell the meanings of index apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origin

From Latin index, meaning a pointer or the forefinger, related to indicō meaning "to point out or show."

Checked 31 Oct 2026 · 3 facts

English index comes from Latin index. en.wiktionary.org
Latin index means a pointer or the forefinger. en.wiktionary.org
Latin indicō means to point out or show. en.wiktionary.org