index |ˈinˌdeks|

noun ( pl. -dexes or esp. in technical use -dices |-dəˌsēz|)

1 an alphabetical list of names, subjects, etc., with references to the places where they occur, typically found at the end of a book.

• an alphabetical list by title, subject, author, or other category of a collection of books or documents, e.g., in a library.

• Computing a set of items each of which specifies one of the records of a file and contains information about its address.

2 an indicator, sign, or measure of something : exam results may serve as an index of the teacher's effectiveness.

• a 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.

• a pointer on an instrument, showing a quantity, a position on a scale, etc.

• [with adj. ] a number giving the magnitude of a physical property or another measured phenomenon in terms of a standard : the oral hygiene index was calculated as the sum of the debris and calculus indices.

3 Mathematics an exponent or other superscript or subscript number appended to a quantity.

4 Printing a symbol shaped like a pointing hand, typically used to draw attention to a note.

5 ( the Index) short for Index Librorum Prohibitorum .

verb [ trans. ]

1 record (names, subjects, etc.) in an index : the list indexes theses under regional headings.

• provide an index to.

2 link 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.

3 [ intrans. ] [often as n. ] ( indexing) (of a machine or part of one) rotate or otherwise move from one predetermined position to another in order to carry out a sequence of operations.

DERIVATIVES

indexable |ˈɪndɛks-| |ɪnˈdɛks-| adjective

indexation |ˌindekˈsā sh ən| |ˈɪnˈdɛkˈseɪʃən| |-ˈseɪʃ(ə)n| noun

indexer |ˈɪnˈdɛksər| noun

indexible |ˈɪnˈdɛksəbəl| adjective

ORIGIN late Middle English : from Latin index, indic- ‘forefinger, informer, sign,’ from in- ‘toward’ + 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 cent.), and figuratively something that serves to point to a fact or conclusion; hence a list of topics in a book (“pointing” to their location).