Definition of index in English:



  • 1(in a book or set of books) an alphabetical list of names, subjects, etc. with reference to the pages on which they are mentioned.

    ‘clear cross references supplemented by a thorough index’
    • ‘Endnotes, bibliography, and an index of names and subjects facilitate scholarly use and quick reference.’
    • ‘For one, the book contains a definitive bibliography and indices on the subject.’
    • ‘Carefully annotated and extensively glossed, it has a chronological table of Ancient Iranian Rulers, a select bibliography, and an index running to 25 pages.’
    • ‘The book has a good index and an extensive bibliography, but no list of illustrations.’
    • ‘The book includes a thorough index, making it a useful tool for researchers and students.’
    • ‘Nearly an hour passed as I sat lost in the pages of the index of that book.’
    • ‘It contains 648 pages of text, spread over 39 chapters and an epilogue, as well as a subject and a name index, each of which takes up 26 pages.’
    • ‘Short serviceable indexes of names, places, and selected subjects complete them.’
    • ‘Separate name and subject indexes provide an efficient tool to guide selective reading.’
    • ‘Intuition finds a disproportion between 5000 illustrations and a subject index of forty pages.’
    • ‘A comprehensive, combined name and subject index forms the concluding section.’
    • ‘It does contain a name index but a subject index would have enhanced its usefulness.’
    • ‘The first part of the book was an index indicating what page each category started on.’
    • ‘The volume concludes with a 200-page name index for on- and off-screen personnel.’
    • ‘The index and bibliography are thorough as well.’
    • ‘The two-page index includes only the names of persons.’
    • ‘Helpful appendices, extensive references, and subject and name indices conclude the volume.’
    • ‘Nine pages of bibliography and both a name index and a subject index round out the book and help make it accessible.’
    • ‘First, the index lists all common names, and all genera, but the species within genera are not listed under each genus.’
    • ‘The book includes a word index and a name and subject index.’
    1. 1.1An alphabetical list by title, author, or other category of a collection of books or documents, for example in a library.
      • ‘Audit documents must include an index that identifies preparers and reviewers and work completion date.’
      • ‘All library items are listed through a main author, title, and subject index.’
      • ‘Could this mean that the differing titles were all the result of a long-dead library clerk having incorrectly entered the book's title details on an index card?’
      • ‘Examples of finding aids include collection indexes, inventories, registers and guides.’
      • ‘A helpful index leads researchers to documents relating to their favorite subjects.’
      • ‘The other documents included in the bundle were not accompanied by any explanatory commentary, but there was an indexto them.’
      • ‘Every title deed should be documented as per this index only.’
      • ‘The authors searched several electronic indexes and reference lists of retrieved publications, and hand searched abstracts and conference proceedings.’
      • ‘Some libraries have created indexes to these works.’
      • ‘Additionally, Regulation 68.2 states that audit documentation must include an index or guide to the documentation.’
      • ‘Disk number one contains the index for the entire collection, including small pictures of every catalogue page.’
      • ‘The paleontological reprint collection is catalogued on index cards and is not yet available in computer format.’
      • ‘When the university received the documents, he says, they were in such disarray that it took years to organize the pages enough to even create an index for the collection.’
      • ‘Libraries that use card indices may seem archaic, but they are actually very modern.’
      • ‘My learned friend has drawn attention to the documents, the indices that were prepared and there was some correspondence about it.’
      • ‘One ongoing goal is the archiving of past issues and the maintenance of an author index online; we continue to work towards the completion of this goal.’
      register, list, listing, inventory, directory, guide, key, catalogue, table of contents
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    2. 1.2Computing A set of items each of which specifies one of the records of a file and contains information about its address.
      • ‘Each search engine has their own set of rules, algorithms, regulations, etc., that they apply to web sites that become part of their indices or databases.’
      • ‘The method includes a tag counting system for indexing structured documents and for implementing the structure indexes within the relational database.’
      • ‘This is because you need to wait for search engines to update their index with the current information.’
      • ‘To achieve the functionality, the author discusses the use of XML files to maintain and parse the index.’
      • ‘I've used backup products with on-line indexes but no way to rebuild them from tape.’
      • ‘A bit-mapped index looks like a spreadsheet with the possible values as column headings and record numbers as row headings.’
  • 2A sign or measure of something.

    ‘exam results may serve as an index of the teacher's effectiveness’
    • ‘Life expectancy is looked on as a measure of civilisation, if not the principal index of cultural achievement.’
    • ‘For the vast majority of us, a handicap is an index of inadequacy - a measure of the distance by which we fall short.’
    • ‘Much of the current research on nonmainstream schools centers on outcome evaluation studies that document school efficacy on indices such as academic success.’
    • ‘Another approach is to evaluate patients when their symptoms and signs raise the index of suspicion of depression.’
    • ‘The state of the love life in this sign is the index of overall happiness.’
    • ‘The viewer can fall in love with resemblances, or can play detective, looking at signs as an index of a process.’
    • ‘The arm circumference of each child was measured as an index of nutritional status.’
    • ‘I show that it is best explicable as an index of old-fashioned attitudes and that its correlation with racism simply shows that it is now old-fashioned to avow openly racist attitudes.’
    • ‘In 1932 one could be a liberal and a progressive and still consistently support the Tuskegee Study; involvement in the project was not necessarily an index of bigotry or racism.’
    • ‘However, she said, the confidence index in many categories stayed below the 100-point level for the 13 th consecutive month.’
    • ‘In spite of the widespread acceptance of withdrawal symptoms as an index of addiction, this consensual faith does not appear to be justified.’
    • ‘The drop in organised sector employment and the growing casualisation of labour is then an index of a general failure of policy since the 1990s - not cause but consequence.’
    • ‘It is an index of censorship's staying power that Joyce can be affirmed and celebrated as a great artist in a context where his enlightened and - yes - liberal views are traduced.’
    guide, clue, hint, indication, indicator, lead, sign, signal, mark, token, evidence, symptom, implication, intimation, suggestion
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    1. 2.1A figure in a system or scale representing the average value of specified prices, shares, or other items as compared with some reference figure.
      ‘the hundred-shares index closed down 9.3’
      • ‘Some charting features allow you to compare individual shares to indices and industry sectors.’
      • ‘These latest trends ignore the impact of oil and gasoline prices, which will begin to show up in the March and April price indexes.’
      • ‘Within the index increases were recorded in dwelling approvals, the share price index, and the money supply.’
      • ‘Investors can bet on individual shares or stock indices, such as the Iseq, Ftse 100, Dow Jones, or Nasdaq going up or down.’
      • ‘And this spring, the core price indexes, which exclude food and fuel, have posted modest increases.’
      • ‘Therefore monetary expansion will distort the structure of relative prices - even if a price index does not change - and might thus precipitate crisis.’
      • ‘The minimum wage differs from one province to another due to differing price indexes and average per capita income.’
      • ‘There was no price change and the index remained unchanged at 385.95.’
      • ‘Companies selected to be added or removed from the index often have wide price swings resulting from investors buying and selling shares of new members.’
      • ‘We excluded food items from the price indexes when the average household food expenditure share was not available.’
      • ‘Despite the fact there are house price and share indices aplenty, comparing the long-term performance of these two assets is not easy.’
      • ‘Obviously, under these conditions monetary pumping can not generate a sustained up-trend in price indices.’
      • ‘For economic and monetary policy formulation, the price index represents a central indicator.’
      • ‘Financial spread betting gives retail investors an opportunity to bet on individual shares, stock indices or currencies.’
      • ‘Price indexes necessarily average out the extremes; they are unable to signal the more subtle price movements and they leave out relevant items such as asset prices.’
      • ‘Also because share prices and indices can be that much more volatile the consequences can be quite devastating should things go wrong.’
      • ‘The share index rose from 894.85 points recorded the previous week, representing a rise of 3.76 per cent.’
      • ‘The construction of price indices is an attempt at the impossible mission of establishing a nonexistent price level.’
      • ‘So this may indicate that those punters betting on shares prices, indices, commodity prices and the like actually do worse than the more traditional sports betting activities.’
      • ‘The entire share prices of the listed and quoted companies remained unchanged leading the share index to remain constant.’
    2. 2.2[with modifier]A number giving the magnitude of a physical property or other measured phenomenon in terms of a standard.
      ‘the oral hygiene index was calculated as the sum of the debris and calculus indices’
      • ‘Although mental development index scores decreased over time for both groups of infants, children prenatally exposed to cocaine had scores that decreased faster.’
      • ‘Efficacy, judged by a standard disease activity index, did not fall off.’
      • ‘Measured stomatal conductance vs. calculated stomatal conductance index under changing light intensities.’
      • ‘First, fixation index estimates showed more random variation across generations with decreasing total numbers of populations.’
      • ‘At the end of March, the air pollution index shot up to 174, a record high.’
      • ‘As controlling behaviour index scores increased, the proportion of women who reported experiencing violent incidents also increased.’
      • ‘Current care provision is inadequate, at least according to dementia care index standards, and urgent action is required.’
      • ‘A total of 100 first-degree adult relatives of 40 gastric cancer index patients were recruited for the study, as were two control groups.’
      • ‘Clinical assessments of the venous ulcers, based on the criteria of the severity scale, were performed and each ulcer was assigned a severity index score.’
      • ‘For all patients, we found no difference in respect of patient enablement index scores.’
      • ‘‘Diversity index scores are just a starting place for looking at diversity,’ Parker emphasizes.’
      • ‘By design, the composite deprivation index increases across tenths with the largest increase between tenths 9 and 10.’
      • ‘Although there was a great deal of scatter, the conservation index scores decreased with increasing distance from the closest exon.’
      • ‘Pain management index scores were measured in one setting.’
      • ‘The emotional response index ranges from 0.0 to 1.0.’
      • ‘Likewise, pain management index scores were not associated with satisfaction in the bivariate correlation analysis.’
      • ‘The number of cigarettes smoked has been ‘significantly related’ to the headache index score and to the number of days with headache each week.’
      • ‘If the history or examination suggest possible hypogonadism, free testosterone or androgen index assessment is preferred.’
      • ‘For instance, higher GI index foods such as a baked potato or a serving of rice with your main meal.’
      • ‘In this experiment, both sperm index evaluation and mating tests were performed on males from each of 146 different genotypes.’
  • 3Mathematics
    An exponent or other superscript or subscript number appended to a quantity.

    • ‘The thesis contains a proof of the fact that for any closed manifold the sum of the indices of a generic vector field is a topological invariant, namely the Euler characteristic.’
    • ‘Step 3: Find the cobasic variable in the equation chosen in step 2 that has the smallest index and a positive coefficient.’
    • ‘If we look at the indices of the Fibonacci numbers, we can directly predict which Fibonacci number will be the square of the hypotenuse.’
    • ‘The paper investigated sets of indices of partial recursive functions and of recursively enumerable sets.’
  • 4A pointer on an instrument, showing a quantity, a position on a scale, etc.

    pointer, indicator, needle, hand, finger, marker
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    1. 4.1Printing A symbol shaped like a pointing hand, used to draw attention to a note.


  • 1Record (names, subjects, etc.) in an index.

    ‘the list indexes theses under regional headings’
    • ‘Each section is indexed with subject listings so the reader can follow up his summaries and selective quotations in the full bibliography of over 1600 items.’
    • ‘Taxonomic names are completely indexed, so that genus and species are given for each subspecific name.’
    • ‘I learn that St. Paul's marriage records, wonderfully indexed, are housed in the Ramsey County courthouse, just down the hill from the Minnesota History Center.’
    • ‘Customer interactions are captured and indexed by topic, subject, date and time, result, etc.’
    • ‘While hundreds of ringtones and graphics are a nice thing to have, none of these are named or indexed in any way that I could find.’
    • ‘Neither subject was indexed nor readily apparent in the table of contents.’
    • ‘The records can also be indexed in various ways simultaneously to ensure instant retrieval of files even in a repository the virtual size of the Grand Canyon.’
    • ‘Subjects indexed cover all aspects of medieval life from art and architecture to iconography, politics, religious life, sexuality, and women in literature.’
    • ‘Smokers' medical records should also be indexed so that they are readily identifiable and easy to retrieve.’
    • ‘Instead of static, talking-head interviews, all are skillfully supplemented with stills and clips, and are indexed by subject.’
    • ‘Initially the data are read and reread to identify and index themes and categories: these may centre on particular phrases, incidents, or types of behaviour.’
    • ‘Alternate names are indexed within the alphabetical listing with references to the proper heading.’
    • ‘All products are indexed and searchable by subject, artist, genre, art movement, size, price and more than 500,000 keywords.’
    • ‘The candidate-advertisers were indexed by name, state and office sought.’
    • ‘One-panel cartoons are also indexed by subject.’
    • ‘As images and sounds move onto the Net and are indexed and subject to search, there will arise rankings of leading images and leading sounds for particular moments in time.’
    1. 1.1Provide an index to.
      ‘she offered help in indexing my text book on bookselling’
      ‘data sets are indexed by subject’
      • ‘They have to catalogue and index the official record with them and have to publish important decisions and functions that affect people.’
      • ‘Articles and essays, as well as recent book reviews, are also indexed on-line.’
      • ‘I fail to see what the harm is in indexing a book and helping people find it.’
      • ‘It's indexed into four chapters, and optional English subtitles are provided.’
      • ‘It's not indexed by name or illustrated, but no matter.’
      • ‘The book begins with a historical perspective on the National Medical Library, followed by a detailed explanation of the way the library indexes journal articles.’
      • ‘‘We're trying to index every book there is, and make it searchable for our users,’ the spokesman added.’
      • ‘The documentary runs 33 minutes, and is indexed into five chapters.’
      • ‘I now feel sad and inadequate that I don't have enough bookmarks to make filing and indexing them an issue.’
      • ‘The researchers sought to highlight the importance of indexing in health education and provide information on where journals were indexed.’
      • ‘So there may be problems associated with the way it indexes saves in some cases.’
      • ‘Because I so copiously mark and index a book, I usually have no need of a bookmark - I simply flip through to find where the marking and indexing stop!’
      • ‘This field actually is a Python dictionary indexed by the name of the channel.’
      • ‘The interview runs 21 minutes and is indexed in five chapters so one can conveniently jump to specific topics.’
  • 2Link the value of (prices, wages, or other payments) automatically to the value of a price index.

    ‘the Supreme Soviet passed legislation indexing wages to prices’
    • ‘It's also the third, following Washington and Oregon, to index its minimum wage to inflation.’
    • ‘Under the current system, initial Social Security benefits are indexed to average wage gains across the economy.’
    • ‘In the present system, benefits after retirement are indexed to the consumer price index.’
    • ‘The list covered staff news letters, invoice printouts, diary management, home to work communications links and of course staff wages cross indexed with PAYE and tax codes.’
    • ‘Florida's new minimum wage is indexed to inflation, so the state will readjust the minimum every fall.’
    • ‘Starting in 1984, however, tax brackets were indexed for inflation.’
    • ‘If the minimum wage were indexed for inflation, it would be around $8.50 today.’
    • ‘Unlike the regular income tax, the alternative minimum tax is not indexed for inflation.’
    • ‘Petrol, cigarette, and alcohol prices are indexed to inflation every year - it takes immediate effect.’
    • ‘The British replacement rate is now lower than 20 per cent and steadily declining because UK basic pensions are indexed to prices rather than to average earnings.’
    • ‘In addition, the majority of public servant pensions are indexed to the salary of the position from which they retired.’
    • ‘In many cases, the pension fund payments are not indexed to inflation, meaning they will not rise with inflation.’
    • ‘And should we index the minimum wage to inflation?’
    • ‘These payments are not indexed for inflation, which will erode the value of the payments.’
    • ‘The municipal workers are demanding that serious negotiations take place and that their wages be fully indexed to the rate of inflation.’
    • ‘The change will not affect the payment of benefits, which will continue to be indexed to the retail price index.’
    • ‘So instead of the Government being fair and deciding that it would index income tax rates as well as all those user charges, it has tried to pretend that it does not need to.’
    • ‘Yet the Labour government refused to index link pensions to average earnings.’
    • ‘Does anyone know why the minimum wage is not indexed to either inflation or wage growth, like social security?’
    • ‘Whereas benefits are indexed to consumer price index inflation, revenue growth is driven by real wage growth.’
  • 3[no object] (of a machine or part of one) move from one predetermined position to another in order to carry out a sequence of operations.

    [as modifier] ‘a lathe with a cross-slide and an indexing arrangement’
    • ‘Disciplined training can achieve a state in which the subconscious mind takes care of gun indexing and trigger control and the conscious mind is just along for the ride.’
    • ‘When a pass is complete, the barrel is rotated or indexed to the position of the next groove.’
    • ‘Newly developed software allows the gage to check parts during indexing without affecting machine layout or cycle time.’


Late Middle English: from Latin index, indic- forefinger, informer, sign, from in- towards + a second element related to dicere say or dicare make known; compare with indicate. The original sense ‘index finger’ (with which one points), came to mean ‘pointer’ (late 16th century), and figuratively something that serves to point to a fact or conclusion; hence a list of topics in a book (‘pointing’ to their location).