Meaning of INDEX in English

I. ˈinˌdeks noun

( plural indexes -ksə̇z ; or in·di·ces -_dəˌsēz ; see sense 8 )

Etymology: Latin indic-, index, from indicare to point out, indicate — more at indicate

1. : index finger 1, forefinger

2. : alidade c


a. : a usually alphabetical list that includes all or nearly all items (as topics, names of people and places) considered of special pertinence and fully or partially covered or merely mentioned in a printed or written work (as a book, catalog, or dissertation), that gives with each item the place (as by page number) where it may be found in the work, and that is usually put at or near the end of the work


(1) : card index

(2) : step index

(3) : tab index

(4) : thumb index

c. : a computer-processed usually alphabetical list especially of bibliographical information ; especially : a bibliographical analysis of groups of publications that is usually published periodically

Index Medicus

4. : something that serves as a pointer or indicator: as

a. : a pointer (as of metal, plastic, wood) that moves along a graduated scale (as of a weighing machine) or that remains fixed while the scale moves past its tip

b. : one of the hands on a timepiece

c. : the gnomon of a sundial

5. obsolete : direct 1


a. : something (as a manner of speaking or acting, a distinctive physical feature) in another person or thing that leads an observer to surmise a particular fact or draw a particular conclusion : sign , token , indication

her fatuous laugh is an index of her pygmy intelligence

the fertility of the land is an index of the country's wealth

b. : a sign whose specific character is causally dependent on the object to which it refers but independent of an interpretant

a bullet hole in a fence is an index that a shot has been fired

— contrasted with icon and symbol


a. : a list of restricted or prohibited or otherwise proscribed material

an index of forbidden books

b. usually capitalized : index librorum prohibitorum

8. plural usually indices : a number or symbol or expression written to the left or right of and above or below or otherwise associated with another number or symbol or expression to indicate use or position in an arrangement or expansion or to indicate a mathematical operation to be performed

the indices 2 and 3 used to locate the element a 23 in the second row and third column of a determinant

3 is the index in the expression ∛5 to specify a cube root of 5

9. or index mark : a character ☞ used to direct particular attention (as to a note or paragraph) and as the seventh in series of the reference marks — called also fist, hand


a. : 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)

a discrepancy index based on the differences between the students' predicted and attained honor-point ratios — Educational & Psychological Measurement

the index of variation … is obtained by considering the positive differences between every pair of incomes in the group and averaging these differences — Economica

an index is a measurable aspect of society which indicates the extent to which certain more complex aspects are present — Mabel Elliott & Francis Merrill

specifically : index number

the index of industrial production increased from 113.2 in December 1950 to 122.0 by November 1951 (1946 . 100) — Americana Annual

— see consumer price index , dow-jones index ; index of refraction

b. : the ratio of one dimension of a thing (as an anatomical structure) to another dimension — see cephalic index

11. : a miniature indication of denomination and value often printed on the corners of playing cards to make it unnecessary to view the full face of each card

II. verb

( -ed/-ing/-es )

transitive verb


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

the book will be indexed in its next edition so as to make it more useful

b. : to list (as the contents of a book) in an index

all persons and places mentioned are carefully indexed


a. : to serve as an index of

wrinkles index advancing age

b. : to point to : indicate

a compass needle that indexes true north

3. : to move (a machine or a piece of work held in a machine tool) so that a specific operation (as the cutting of gear teeth) will be repeated at definite intervals of space

4. : to determine the fertility or yielding ability or disease resistance or some other character of (a plant or seed) by planting and testing a sample in advance of release for general use — used especially of potatoes

indexing potato eyes

indexing a potato of each hill

intransitive verb

: to index something

III. transitive verb

: to regulate (as wages or prices) by indexation

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.