index

[ in-deks ]

/ ˈɪn dɛks /

noun, plural in·dex·es, in·di·ces [in-duh-seez]. /ˈɪn dəˌsiz/.

(in a nonfiction book, monograph, etc.) a more or less detailed alphabetical listing of names, places, and topics along with the numbers of the pages on which they are mentioned or discussed, usually included in or constituting the back matter.

a sequential arrangement of material, especially in alphabetical or numerical order.

something used or serving to point out; a sign, token, or indication: a true index of his character.

something that directs attention to some fact, condition, etc.; a guiding principle.

a pointer or indicator in a scientific instrument.

a piece of wood, metal, or the like, serving as a pointer or indicator.

Digital Technology.

a value that identifies and is used to locate a particular element within a data array or table.
a reference table that contains the keys or references needed to address data items.
the part of a search engine where website addresses are cataloged with their associated keywords in order to quickly retrieve the most relevant web pages when a user submits a search query.

Also called fist, hand .Printing. a sign in the shape of a hand with extended index finger, used to point out a particular note, paragraph, etc.

a light, smooth cardboard stock.

the forefinger.

a number or formula expressing some property, ratio, etc., of something indicated: index of growth; index of intelligence.

Statistics. index number.

Economics. price index.

Algebra.

an exponent.
the integer n in a radical  defining the n-th root: ∛ is a radical having index three.
a subscript or superscript indicating the position of an object in a series of similar objects, as the subscripts 1, 2, and 3 in the series x1, x2, x3.
winding number.

Horology. a leverlike regulator for a hairspring.

(initial capital letter)Roman Catholic Church.

(usually initial capital letter) any list of forbidden or otherwise restricted material deemed morally or politically harmful by authorities: an Index of disapproved books relating to Communism.

Optics. index of refraction.

Obsolete.

a table of contents.
a preface or prologue.

verb (used with object)

to provide with an index, as a book.

to enter in an index, as a name or topic.

to serve to indicate: warm breezes indexing the approach of spring.

to place (a book) on an official list as politically or morally harmful: The commissar insisted on indexing the book.

to rotate (work) on a milling machine in order to repeat the milling operation at a new position.

Economics. to adjust (wages, taxes, etc.) automatically according to changes in the cost-of-living level or another economic indicator, especially to offset inflation.

Digital Technology. (of a search engine) to catalog (a website) using keywords: Search engines use automated algorithms to index billions of web pages, but that still accounts for only a fraction of the content on the internet.

QUIZZES

CAN YOU GUESS THESE WORDS FROM AROUND THE US?

American English is not always as it appears to be ... get to know regional words in this quiz!

Question 1 of 10

A bet is synonymous with a wager, but what does it mean in New York?

Often it means something is impossible.

It’s another way to agree with someone.

It serves as an apology.

TAKE THE QUIZ TO FIND OUT

Origin of index

First recorded in 1350–1400; Middle English, from Latin: “informer, pointer,” equivalent to in-in-² + -dec- (combining form of dic-, “show, declare, indicate,” akin to teach;see indicate) + -s nominative singular ending;

OTHER WORDS FROM index

in·dex·a·ble, adjectivein·dex·er, nounin·dex·i·cal, adjectivein·dex·i·cal·ly, adverb

in·dex·less, adjectivenon·in·dexed, adjectiveo·ver·in·dex, verb (used with object)o·ver·in·dex·ing, nounre·in·dex, verb (used with object)un·in·dexed, adjectivewell-indexed, adjective

WORDS THAT MAY BE CONFUSED WITH index

appendix, index , supplement

Words nearby index

indeterminate equation, indeterminate sentence, indeterminate vowel, indetermination, indeterminism, index, indexation, index card, index case, index crime, Index Expurgatorius

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for index

The changes won’t disrupt the level of the index, the company says.
Salesforce, Amgen, and Honeywell Int’l will join Dow Jones Industrial Average|Andrew Nusca|August 24, 2020|Fortune
In its updated 2020 wildfire mitigation plan, SDG&E said it developed a vegetation risk index, which could help identify where it needs to do the 25-foot pruning.
Watchdog Warns: SDG&E’s Tree-Trimming Plan Could Worsen Wildfires|MacKenzie Elmer|August 24, 2020|Voice of San Diego
SAC spun the index off into a separate company in 2019 to further develop the technology behind it, and is promoting its adoption by other industries.
A greener and more compassionate apparel industry|Tate Ryan-Mosley|August 19, 2020|MIT Technology Review
On those two previous occasions, value beat the index by the biggest margin.
The champ’s big comeback: Why beaten-down value stocks are poised to thrive|Shawn Tully|August 18, 2020|Fortune

By contrast, health care—the second-largest sector—carries a market cap of just under $4 trillion and represents only 14% of the index.
‘It’s clicks versus bricks’: Why tech stocks won’t be fading anytime soon|reymashayekhi|August 17, 2020|Fortune
He stuck his index finger in the red welt around the spot where bin Laden shot me.
I Shot Bin Laden|Elliot Ackerman|November 16, 2014|DAILY BEAST
Abu Hassar began to twirl it between his index finger and thumb.
The Fourth War: My Lunch with a Jihadi|Elliot Ackerman|January 21, 2014|DAILY BEAST
When the advocacy group launched this Index in 2002, only 13 companies did.
They’re Here. They’re Investable. Get Used to It.|Credit Suisse|December 16, 2013|DAILY BEAST
That one line merits a single page reference for Tolstoy in the index.
John Sutherland‘s Enjoyable Little History of Literature|Malcolm Forbes|November 29, 2013|DAILY BEAST
Pundit Niall Ferguson constructed a Twitter-based index that calculates relative prestige as the ratio of tweets to followers.
How Twitter Got Huge|Daniel Gross|November 7, 2013|DAILY BEAST
Slowly her right hand rose above her head with its index finger extended and slowly came down to her side.
The Light in the Clearing|Irving Bacheller
These facts are related, says the Commentator, as an index to or test of the honesty of metal-workers.
Hindu Law and Judicature|Yjnavalkya
His blue eyes sparkled and flashed, his clean-cut mobile features were an index to his slightest shades of feeling and expression.
Adventure|Jack London
The ball had pierced my hand by the metacarpus under the index finger, and had broken the first phalanges.
The Memoires of Casanova, Complete|Jacques Casanova de Seingalt
First page of index : 'ullimentary' changed to 'Allimentary'; also 'ilstrating' channged to 'illustrating'.
The Nervous Child|Hector Charles Cameron

British Dictionary definitions for index

index

/ (ˈɪndɛks) /

noun plural -dexes or -dices (-dɪˌsiːz)

an alphabetical list of persons, places, subjects, etc, mentioned in the text of a printed work, usually at the back, and indicating where in the work they are referred to

See thumb index

library science a systematic list of book titles or author's names, giving cross-references and the location of each book; catalogue

an indication, sign, or token

a pointer, needle, or other indicator, as on an instrument

maths

another name for exponent (def. 4)
a number or variable placed as a superscript to the left of a radical sign indicating by its value the root to be extracted, as in ³√8 = 2
a subscript or superscript to the right of a variable to express a set of variables, as in using x i for x 1, x 2, x 3, etc

a numerical scale by means of which variables, such as levels of the cost of living, can be compared with each other or with some base number

a number or ratio indicating a specific characteristic, property, etcrefractive index

Also called: fist a printer's mark (☛) used to indicate notes, paragraphs, etc

obsolete a table of contents or preface

verb (tr)

to put an index in (a book)

to enter (a word, item, etc) in an index

to point out; indicate

to index-link

to move (a machine or a workpiece held in a machine tool) so that one particular operation will be repeated at certain defined intervals

Derived forms of index

indexer, nounindexless, adjective

Word Origin for index

C16: from Latin: pointer, hence forefinger, title, index, from indicāre to disclose, show; see indicate

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for index

index

[ ĭn′dĕks′ ]

n. pl. in•dex•es

A guide, standard, indicator, symbol, or number indicating the relation of one part or thing to another in respect to size, capacity, or function.

A core or mold used to record or maintain the relative position of a tooth or teeth to one another or to a cast.

A guide, usually made of plaster, used to reposition teeth, casts, or parts.

The index finger.

Other words from index

in′dex′ v.

Cultural definitions for index

index

An alphabetical list of subjects treated in a book. It usually appears at the end of the book and identifies page numbers on which information about each subject appears.

MEANINGS

WORD GAMES

LEARN

WRITING

WORD OF THE DAY

index