index
UK[ˈɪndɛks]US[ˈɪndɛks]
n
An alphabetical list of names, subjects, etc., at the back of a book, showing on which page they are mentioned.
n
A sign or measure that something else can be judged by.
n
A system that shows the level of prices, wages, etc. so that they can be compared with those of a previous date.
v
To make an index for a book or collection.
v
To link wages, pensions, or other payments to the level of prices.
Morpheme Breakdown
in
dex
in
in
dex
to point out
Etymology
The word 'index' has a direct lineage from Latin, where it meant 'one who points out', 'informer', or 'forefinger'. It is a compound of the prefix 'in-' (meaning 'in' or 'towards') and the root from the verb 'dicere' (to say, to point out). The literal sense of 'pointer' evolved logically: the forefinger points, a book's index points to locations, and an economic indicator points to a trend. This semantic journey from a physical pointer to an abstract guide or measure illustrates how a concrete action transformed into a tool for organization and reference.
Analysis
Structure: in + dex
- in: Latin origin. A prefix meaning 'in', 'into', 'towards', or 'upon'.
- dex: Latin origin. From the root deik-/dic- meaning 'to point out', 'to show', or 'to pronounce'. It functions as the core root indicating the act of pointing or showing.
Examples
Check the index to find the chapter on climate change.
The stock market index fell by two percent today.
The book is fully indexed for easy reference.