1

index

play
noun in·dex \ˈin-ˌdeks\

Definition of index

plural

indexes

or

indices

play \ˈin-də-ˌsēz\
  1. 1a :  a device (such as the pointer on a scale or the gnomon of a sundial) that serves to indicate a value or quantityb :  something (such as a physical feature or a mode of expression) that leads one to a particular fact or conclusion :  indication

  2. 2 :  a list (as of bibliographical information or citations to a body of literature) arranged usually in alphabetical order of some specified datum (such as author, subject, or keyword): such asa :  a list of items (such as topics or names) treated in a printed work that gives for each item the page number where it may be foundb :  thumb indexc :  a bibliographical analysis of groups of publications that is usually published periodicallyd :  a list of publicly traded companies and their stock prices

  3. 3 :  a list of restricted or prohibited material; specifically, capitalized :  a formerly published list of books the reading of which was prohibited or restricted for Roman Catholics by the church authorities

  4. 4 plural usually indices :  a number or symbol or expression (such as an exponent) associated with another to indicate a mathematical operation to be performed or to indicate use or position in an arrangement 3 is the index of the expression ∛5 to indicate the cube root of 5

  5. 5 :  a character F used to direct attention to a note or paragraph —called also fist

  6. 6a :  a number (such as a ratio) derived from a series of observations and used as an indicator or measure; specifically :  index numberb :  the ratio of one dimension of a thing (such as an anatomical structure) to another dimension

Examples of index in a sentence

  1. Look up the recipe for potato soup in the index.

  2. Potato soup is listed under soup in the index.

  3. The card catalog is an index to the materials in the library.

  4. the index on a scale

Origin and Etymology of index

Latin indic-, index, from indicare to indicate


First Known Use: 1561


2

index

verb in·dex

Definition of index

  1. transitive verb
  2. 1a :  to provide with an indexb :  to list in an index all persons and places mentioned are carefully indexed

  3. 2 :  to serve as an index of

  4. 3 :  to regulate (wages, prices, interest rates, etc.) by indexation

  5. intransitive verb
  6. :  to index something

indexer

noun

Examples of index in a sentence

  1. This search engine has indexed hundreds of millions of Web sites.

  2. indexed all the books in the library by category

1720

First Known Use of index

1720



INDEX Defined for English Language Learners


2

index

verb in·dex

Definition of index for English Language Learners

  • : to provide an index for (something, such as a book)

  • : to list or include (something) in an index

  • : to link wages, benefits, etc., to a measurement of changes in the price of goods and services so that they increase at the same rate


INDEX Defined for Kids

1

index

play
noun in·dex \ˈin-ˌdeks\

Definition of index for Students

plural

indexes

or

indices

\ˈin-də-ˌsēz\
  1. 1 :  a list of names or topics (as in a book) given in alphabetical order and showing where each is to be found

  2. 2 :  pointer 1 the index on a scale

  3. 3 :  1sign 3, indication Prices are an index of business conditions.


2

index

play
verb in·dex

Definition of index for Students

indexed

;

indexing

  1. 1 :  to provide (as a book) with an index

  2. 2 :  to list in an index The topics are indexed.


Medical Dictionary

index

play
noun in·dex \ˈin-ˌdeks\

Medical Definition of index

plural

indexes

or

indices

\-də-ˌsēz\play
  1. 1:  index finger

  2. 2:  a list (as of bibliographical information or citations to a body of literature) arranged usually in alphabetical order of some specified datum (as author, subject, or keyword) Index Medicus of the United States National Library of Medicine

  3. 3a:  a ratio or other number derived from a series of observations and used as an indicator or measure (as of a condition, property, or phenomenon) physiochemical indexes of the urine, the blood, and the gastric juice—Journal of the American Medical Associationb:  the ratio of one dimension of a thing (as an anatomical structure) to another dimension—see cephalic index, cranial index


Law Dictionary

1

index

noun in·dex

Legal Definition of index

  1. :  a numerical measure or indicator (as of inflation or economic performance) — see also consumer price index


2

index

transitive verb in·dex

Legal Definition of index

  1. :  to link (as wages, rates, or investments) to an index under the contract wages were indexed to inflation



Seen and Heard

What made you want to look up index? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

acid in temper, mood, or tone

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

  • peter-bruegel-tower-of-babel-painting
  • What language does pajama come from?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Syn City

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!