index

pronunciation

How to pronounce index in British English: UK [ˈɪndeks] word uk audio image

How to pronounce index in American English: US [ˈɪndeks] word us audio image

Noun:

a numerical scale used to compare variables with one another or with some reference number
a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time
a mathematical notation indicating the number of times a quantity is multiplied by itself
an alphabetical listing of names and topics along with page numbers where they are discussed
the finger next to the thumb
Verb:

list in an index
provide with an index
adjust through indexation

Word Origin

index: index: [16] Latin index originally meant ‘indicator’, and hence more specifically ‘forefinger’ – the finger used for pointing things out. It was based on the same stem, *dik- ‘point out’, as produced Latin dīcere ‘say’ (source of English diction, dictionary, etc). The metaphorically extended sense ‘list of contents’ had already developed in Latin before English took it over. Indicate is a parallel but apparently independent formation.=> diction, dictionary, indicate

index (n.): late 14c., "the forefinger," from Latin index (genitive indicis) "forefinger, pointer, sign, list," literally "anything which points out," from indicare "point out" (see indication). Meaning "list of a book's contents" is first attested 1570s, from Latin phrases such as Index Nominum "Index of Names," index expurgatorius "specification of passages to be deleted from works otherwise permitted." Scientific sense (refractive index, etc.) is from 1829; economic sense (cost-of-living index, etc.) is from 1870, from the scientific usage, from sense "an indicator." The Church sense of "forbidden books" is from index librorum prohibitorum, first published 1564 by authority of Pius IV.

index (v.): "compile an index," 1720, from index (n.). Related: Indexed; indexing.